Bondline - User contributions [en]

Rigging Checks and adjustments

2006-01-11T16:45:47Z

66.167.55.183:

'''Rigging Checks'''

'''Mechanical Difficulty:''' [[image:wrench.jpg]]

'''This is a job which an owner/pilot can do without any additional supervision or sign off, because you are only CHECKING the control travel, not making adjustments to the primary flight controls.'''

Checking the rigging on a Grumman is a very simple job if you have the factory templates shown in the Maintenance Manual. They are available for rent from [http://www.fletchair.com/onlineBrochure/08-11_Sec12.pdf FletchAir] on a weekly basis.

Many rigging checks can be made without the factory templates, with slightly more effort. Each year at the [http://www.aya.org/events/20060710-t82/ AYA Convention], the rigging templates and the Rigging Check volunteers are available to help owners check for discrepancies in their rigging of their planes.

The goal of rigging checks (and adjustments as needed) is to bring the plane into compliance with its Type Certificate Data Sheet specs, and to improve the handling and performance of the plane. In the hundreds of planes checked at the AYA conventions since 1998 at the first Cody Convention when I spearheaded the effort to start the riging checks, I have yet to see ONE PLANE that had correct rigging on all surfaces. All that I have personally checked had at least 2 measurements out of spec. Too little or too much control displacement, but always at least 2 out of spec!

Significant performance changes can be obtained by removing the errors and getting theplane correctly rigged. At conventions its been sort of a tradition to help correct the plane that "wins" the worst rigged plane award. There have been stabilizers without enough UP travel that caused the pilot to always land at 90 mph, planes with bent outboard aileron bearing brackets that had made it impossible to fly "hands off" since the plane was purchased by its current owner, and an amazing array of other rigging errors that induced all sorts of strange handling characteristics that the owners just put up with. Then there were those rigged so poorly that they had significant performance deficits. Some people have spent many thousands of dollars for "speed mods", and found more performance in FREE rigging adjustments than in all their combined speed mod improvements.

'''Rigging Adjustments'''

'''Mechanical Difficulty:''' [[image:wrench2.jpg]] '''-''' [[image: wrench3.jpg]]

'''Any adjustments to the flight controls requires appropriate certificates and a log book sign off. You will need an Airframe mechanic to supervise and sign off the following work. '''

After rigging checks determine that there are control travels outside the specified limits, the next step is to attempt to correct the errors. On the elevator and rudder, the adjustments are under the plastic tail cone. They consist of 4 stop bolts with jam nuts on them to prevent unwanted movement of the stops. Loosen the jam nut on the stop in question (7/16" offset box end wrench is the best tool), and then turn the stop bolt IN for more travel and OUT for less. Re-check with template or protractor to confirm the adjustment, and when correct, re-snug the jam nut. Most of the Type Certificate Data Sheet specs give a range of travel that is acceptable. Adjusting to the maximum travel will give the most control authority, and may provide the last bit of control that you need some day.

The Elevator trim can not be "adjusted" for total travel, but it can be adjusted to center the travel such that the UP and DN limits are correct. The most common cause of elevator trim miss-rigging is lack of maintenance. The trim wheel in the console between the front seats drives the indicator, and it also drives a pair of bevel gears that convert the motion of the wheel into rotation of the trim drive, a long aluminum tube just above the floor in the tail cone. Failure to clean the old dried grease and grit from the gears, from the bearings that support the trim drive tube, and from the threads and actuator nut in the plastic tail cone can lead to excess torque required to move the trim. This can cause the bevel gears to slip, and cause the trim position indicator to no longer be sync'd with the actual position of the trim. The fix is to clean all the trim drive parts and re-lubricate them, and then set the indicator to match the elevator trim by disengaging the bevel gears and re-meshing them. Its also important to check the backlash in the gears and adjust the depth of their engagement, so that the trim won't easily return to its mis-adjusted state.

Flaps are rigged by adjusting 2 pairs of Heim joints, one pair for each side. The first step is to inspect for the correct AMOUNT of total travel.

Aileron rigging is subject to several possible faults.

<To be continued>

Rigging Checks and adjustments

2006-01-11T16:34:05Z

66.167.55.183:

Rigging Checks and adjustments

2006-01-11T01:37:32Z

66.167.55.183:

'''Rigging Checks'''

'''Mechanical Difficulty:''' [[image:wrench.jpg]]

'''This is a job which an owner/pilot can do without any additional supervision or sign off. Because you are only CHECKING the control travel, not making adjustments to the primary flight controls.'''

Checking the rigging on a Grumman is a very simple job if you have the factory templates shown in the Maintenance Manual. They are available for rent from [http://www.fletchair.com/onlineBrochure/08-11_Sec12.pdf FletchAir] on a weekly basis.

Many rigging checks can be made without the factory templates, with slightly more effort. Each year at the [http://www.aya.org/events/20060710-t82/ AYA Convention], the rigging templates and the Rigging Check volunteers are available to help owners check for discrepancies in their rigging of their planes.

The goal of rigging checks (and adjustments as needed) is to bring the plane into compliance with its Type Certificate Data Sheet specs, and to improve the handling and performance of the plane. This is a job which an owner/pilot can do without any additional supervision or sign off. Because you are only CHECKING the control travel, not making adjustments to the primary flight controls.

'''Rigging Adjustments'''

'''Mechanical Difficulty:''' [[image:wrench2.jpg]] '''-''' [[image: wrench3.jpg]]

'''Any adjustments to the flight controls requires appropriate certificates and a log book sign off. You will need an Airframe mechanic to supervise and sign off the following work. '''

After rigging checks determine that there are control travels outside the specified limits, the next step is to attempt to correct the errors. On the elevator and rudder, the adjustments are under the plastic tail cone. They consist of 4 stop bolts with jam nuts on them to prevent unwanted movement of the stops. Loosen the jam nut on the stop in question (7/16" offset box end wrench is the best tool), and then turn the stop bolt IN for more travel and OUT for less. Re-check with template or protractor to confirm the adjustment, and when correct, re-snug the jam nut. Most of the Type Certificate Data Sheet specs give a range of travel that is acceptable. Adjusting to the maximum travel will give the most control authority, and may provide the last bit of control that you need some day.

<To be continued>

Rigging Checks and adjustments

2006-01-11T01:36:23Z

66.167.55.183:

Rigging Checks and adjustments

2006-01-11T01:34:36Z

66.167.55.183:

'''Rigging Checks'''

'''Mechanical Difficulty:''' [[image:wrench.jpg]]

Checking the rigging on a Grumman is a very simple job if you have the factory templates shown in the Maintenance Manual. They are available for rent from [http://www.fletchair.com/onlineBrochure/08-11_Sec12.pdf FletchAir] on a weekly basis.

Many rigging checks can be made without the factory templates, with slightly more effort. Each year at the [http://www.aya.org/events/20060710-t82/ AYA Convention], the rigging templates and the Rigging Check volunteers are available to help owners check for discrepancies in their rigging of their planes.

The goal of rigging checks (and adjustments as needed) is to bring the plane into compliance with its Type Certificate Data Sheet specs, and to improve the handling and performance of the plane. This is a job which an owner/pilot can do without any additional supervision or sign off. Because you are only CHECKING the control travel, not making adjustments to the primary flight controls.

'''Rigging Adjustments'''

'''Mechanical Difficulty:''' [[image:wrench2.jpg]] '''-''' [[image: wrench3.jpg]]

'''Any adjustments to the flight controls requires appropriate certificates and a log book sign off. You will need an Airframe mechanic to supervise and sign off the following work. '''

After rigging checks determine that there are control travels outside the specified limits, the next step is to attempt to correct the errors. On the elevator and rudder, the adjustments are under the plastic tail cone. They consist of 4 stop bolts with jam nuts on them to prevent unwanted movement of the stops. Loosen the jam nut on the stop in question (7/16" offset box end wrench is the best tool), and then turn the stop bolt IN for more travel and OUT for less. Re-check with template or protractor to confirm the adjustment, and when correct, re-snug the jam nut. Most of the Type Certificate Data Sheet specs give a range of travel that is acceptable. Adjusting to the maximum travel will give the most control authority, and may provide the last bit of control that you need some day.

Rigging Checks and adjustments

2006-01-11T01:30:35Z

66.167.55.183:

'''Rigging Checks'''

'''Mechanical Difficulty:''' [[image:wrench.jpg]]

Checking the rigging on a Grumman is a very simple job if you have the factory templates shown in the Maintenance Manual. They are available for rent from [http://www.fletchair.com/onlineBrochure/08-11_Sec12.pdf FletchAir] on a weekly basis.

Many rigging checks can be made without the factory templates, with slightly more effort. Each year at the [http://www.aya.org/events/20060710-t82/ AYA Convention], the rigging templates and the Rigging Check volunteers are available to help owners check for discrepancies in their rigging of their planes.

The goal of rigging checks (and adjustments as needed) is to bring the plane into compliance with its Type Certificate Data Sheet specs, and to improve the handling and performance of the plane.

'''Rigging Adjustments'''

'''Mechanical Difficulty:''' [[image:wrench2.jpg]] '''-''' [[image: wrench3.jpg]]

After rigging checks determine that there are control travels outside the specified limits, the next step is to attempt to correct the errors. On the elevator and rudder, the adjustments are under the plastic tail cone. They consist of 4 stop bolts with jam nuts on them to prevent unwanted movement of the stops. Loosen the jam nut on the stop in question (7/16" offset box end wrench is the best tool), and then turn the stop bolt IN for more travel and OUT for less. Re-check with template or protractor to confirm the adjustment, and when correct, re-snug the jam nut. Most of the Type Certificate Data Sheet specs give a range of travel that is acceptable. Adjusting to the maximum travel will give the most control authority, and may provide the last bit of control that you need some day.

Rigging Checks and adjustments

2006-01-11T01:18:20Z

66.167.55.183:

Rigging Checks and adjustments

2006-01-11T01:09:51Z

66.167.55.183: Rigging Checks and Adjustments

'''Rigging Checks'''

'''Mechanical Difficulty:''' [[image:wrench.jpg]]

'''Rigging Adjustments'''

'''Mechanical Difficulty:''' [[image:wrench2.jpg]]

Bondline

2006-01-11T01:07:35Z

66.167.55.183:

[[Image:P9130251.JPG|thumb|400 px|Orange Airplane]]

Bondline is the place for Grumman owners and pilots to share their knowledge.

* [[337s]]

* [[Brake System]]

* [[Charging Systems]]

* [[Fuel Tank Leaks]]

* [[Interior Trim]]

* [[Pre-Purchase Inspections]]

* [[Rigging Checks and adjustments]]

Brake Master and Slave Cylinders

2006-01-10T23:39:58Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=794f31fd6027b03033374ec96690b9fe&rgn=div8&view=text&node=14:1.0.1.3.20.0.363.10&idno=14 FARs require] the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the [http://www.aircraftspruce.com/catalog/hapages/an818.php AN 818-4D] line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an [http://www.performanceplumbing.com/AN_Adapters_2.html AN 806-4D] plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the [http://www.parker.com/ag/wbd/cleveland/pdf/Wbcov.pdf Cleveland Wheel and Brake Parts Catalog] for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. If the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, and you can ask nicely for replacement data plates, they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring. Its important to use the correct part number that is made of the right material, and not just some "hardware store" o-ring. The early planes use a 1.5" piston and the later models use a 2" piston. The Mil-Spec is an MS28775 in either [http://www.wicksaircraft.com/catalog/product_detail.php/pid=6320~subid=1689/index.html?PHPSESSID=544f063ebd63b7bfa3ced8221afb67b4 -222] or [http://www.wicksaircraft.com/catalog/product_detail.php/pid=6321~subid=1689/index.html -224]. It is important that the o-ring not be twisted in its groove. Lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off the excess fluid and install the assembly on the plane.

Refer to the section on [http://www.bondline.org/index.php/%3D%3D_Fixing_soft_brakes_caused_by_fluid_leaks_and_air_in_the_system_%3D%3D bleeding the brakes] for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that the pilot's side master cylinder output in hooked to the co-pilot's side master cylinder inlet, and the co-pilot's side master cylinder output is connected to the brake caliper by flex and hard lines.

This means that low fluid in the pilot's side master cylinder can cause a loss of brake effectiveness and a soft pedal, and the co-pilot's side brakes can continue to work.

Removing the brake master cylinders requires disconnecting the flex line from the output, and on the co-pilot's side, also disconnecting the flex line to the input. The master cylinder must be disconnected from its bracket on the floor, and from the brake pedal. The installation hardware can vary from year model to year model, with some having Clevis Pins, some Clevis Bolts, and some AN3 bolts. In all cases the greatest difficulty is in reaching the hardware. The master cylinders are on the firewall side of the rudder pedals, so its awkward to reach the hardware.

Some [http://www.performanceplumbing.com/AN_Adapters_2.html AN806-4D] flare plugs are handy to seal the flex lines as they are disconnected. Unless the fluid has all been drained from the brake system, several ounces of 5606 fluid will leak out when the lines are disconnected.

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T23:39:25Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=794f31fd6027b03033374ec96690b9fe&rgn=div8&view=text&node=14:1.0.1.3.20.0.363.10&idno=14 FARs require] the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the [http://www.aircraftspruce.com/catalog/hapages/an818.php AN 818-4D] line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an [http://www.performanceplumbing.com/AN_Adapters_2.html AN 806-4D] plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the [http://www.parker.com/ag/wbd/cleveland/pdf/Wbcov.pdf Cleveland Wheel and Brake Parts Catalog] for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. If the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, and you can ask nicely for replacement data plates, they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring. Its important to use the correct part number that is made of the right material, and not just some "hardware store" o-ring. The early planes use a 1.5" piston and the later models use a 2" piston. The Mil-Spec is an MS28775 in either [http://www.wicksaircraft.com/catalog/product_detail.php/pid=6320~subid=1689/index.html?PHPSESSID=544f063ebd63b7bfa3ced8221afb67b4 -222] or [http://www.wicksaircraft.com/catalog/product_detail.php/pid=6321~subid=1689/index.html -224]. It is important that the o-ring not be twisted in its groove. Lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off the excess fluid and install the assembly on the plane.

Refer to the section on [http://www.bondline.org/index.php/%3D%3D_Fixing_soft_brakes_caused_by_fluid_leaks_and_air_in_the_system_%3D%3D bleeding the brakes] for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that the pilot's side master cylinder output in hooked to the co-pilot's side master cylinder inlet, and the co-pilot's side master cylinder output is connected to the brake caliper by flex and hard lines.

This means that low fluid in the pilot's side master cylinder can cause a loss of brake effectiveness and a soft pedal, and the co-pilot's side brakes can continue to work.

Removing the brake master cylinders requires disconnecting the flex line from the output, and on the co-pilot's side, also disconnecting the flex line to the input. The master cylinder must be disconnected from its bracket on the floor, and from the brake pedal. The installation hardware can vary from year model to year model, with some having Clevis Pins, some Clevis Bolts, and some AN3 bolts. In all cases the greatest difficulty is in reaching the hardware. The master cylinders are on the firewall side of the rudder pedals, so its awkward to reach the hardware.

Some AN806-4D flare plugs are handy to seal the flex lines as they are disconnected. Unless the fluid has all been drained from the brake system, several ounces of 5606 fluid will leak out when the lines are disconnected.

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T23:28:57Z

66.167.55.183:

Brake Master and Slave Cylinders

2006-01-10T23:26:36Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=794f31fd6027b03033374ec96690b9fe&rgn=div8&view=text&node=14:1.0.1.3.20.0.363.10&idno=14 FARs require] the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the [http://www.aircraftspruce.com/catalog/hapages/an818.php AN 818-4D] line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an [http://www.performanceplumbing.com/AN_Adapters_2.html AN 806-4D] plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the [http://www.parker.com/ag/wbd/cleveland/pdf/Wbcov.pdf Cleveland Wheel and Brake Parts Catalog] for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. If the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, and you can ask nicely for replacement data plates, they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring. Its important to use the correct part number that is made of the right material, and not just some "hardware store" o-ring. The early planes use a 1.5" piston and the later models use a 2" piston. The Mil-Spec is an MS28775 in either [http://www.wicksaircraft.com/catalog/product_detail.php/pid=6320~subid=1689/index.html?PHPSESSID=544f063ebd63b7bfa3ced8221afb67b4 -222] or [http://www.wicksaircraft.com/catalog/product_detail.php/pid=6321~subid=1689/index.html -224]. and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on [http://www.bondline.org/index.php/%3D%3D_Fixing_soft_brakes_caused_by_fluid_leaks_and_air_in_the_system_%3D%3D bleeding the brakes] for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T23:24:39Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=794f31fd6027b03033374ec96690b9fe&rgn=div8&view=text&node=14:1.0.1.3.20.0.363.10&idno=14 FARs require] the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the [http://www.aircraftspruce.com/catalog/hapages/an818.php AN 818-4D] line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an [http://www.performanceplumbing.com/AN_Adapters_2.html AN 806-4D] plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the [http://www.parker.com/ag/wbd/cleveland/pdf/Wbcov.pdf Cleveland Wheel and Brake Parts Catalog] for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. If the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, and you can ask nicely for replacement data plates, they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring. Its important to use the correct part number that is made of the right material, and not just some "hardware store" o-ring. The early planes use a 1.5" piston and the later models use a 1.75" piston. The Mil-Spec is an MS28775 in either [http://www.wicksaircraft.com/catalog/product_detail.php/pid=6320~subid=1689/index.html?PHPSESSID=544f063ebd63b7bfa3ced8221afb67b4 -222] or -224. and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on [http://www.bondline.org/index.php/%3D%3D_Fixing_soft_brakes_caused_by_fluid_leaks_and_air_in_the_system_%3D%3D bleeding the brakes] for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T23:15:42Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=794f31fd6027b03033374ec96690b9fe&rgn=div8&view=text&node=14:1.0.1.3.20.0.363.10&idno=14 FARs require] the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the [http://www.aircraftspruce.com/catalog/hapages/an818.php AN 818-4D] line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an [http://www.performanceplumbing.com/AN_Adapters_2.html AN 806-4D] plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the [http://www.parker.com/ag/wbd/cleveland/pdf/Wbcov.pdf Cleveland Wheel and Brake Parts Catalog] for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. If the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on [http://www.bondline.org/index.php/%3D%3D_Fixing_soft_brakes_caused_by_fluid_leaks_and_air_in_the_system_%3D%3D bleeding the brakes] for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake System

2006-01-10T23:14:24Z

66.167.55.183:

* [[== Fixing soft brakes caused by fluid leaks and air in the system ==]]

* [[== Cleaning, re-sealing and repairing Master and Slave cylinders ==]]

Brake Master and Slave Cylinders

2006-01-10T23:13:43Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=794f31fd6027b03033374ec96690b9fe&rgn=div8&view=text&node=14:1.0.1.3.20.0.363.10&idno=14 FARs require] the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the [http://www.aircraftspruce.com/catalog/hapages/an818.php AN 818-4D] line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an [http://www.performanceplumbing.com/AN_Adapters_2.html AN 806-4D] plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the [http://www.parker.com/ag/wbd/cleveland/pdf/Wbcov.pdf Cleveland Wheel and Brake Parts Catalog] for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on [http://www.bondline.org/index.php/%3D%3D_Fixing_soft_brakes_caused_by_fluid_leaks_and_air_in_the_system_%3D%3D bleeding the brakes] for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T23:12:31Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=794f31fd6027b03033374ec96690b9fe&rgn=div8&view=text&node=14:1.0.1.3.20.0.363.10&idno=14 FARs require] the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the [http://www.aircraftspruce.com/catalog/hapages/an818.php AN 818-4D] line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an [http://www.performanceplumbing.com/AN_Adapters_2.html AN 806-4D] plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the [http://www.parker.com/ag/wbd/cleveland/pdf/Wbcov.pdf Cleveland Wheel and Brake Parts Catalog] for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on bleeding the brakes for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T23:11:28Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=794f31fd6027b03033374ec96690b9fe&rgn=div8&view=text&node=14:1.0.1.3.20.0.363.10&idno=14 FARs require] the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the [http://www.aircraftspruce.com/catalog/hapages/an818.php AN 818-4D] line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an [http://www.performanceplumbing.com/AN_Adapters_2.html AN 806-4D] plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the Cleveland Wheel and Brake Parts Catalog for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on bleeding the brakes for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T23:10:29Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=794f31fd6027b03033374ec96690b9fe&rgn=div8&view=text&node=14:1.0.1.3.20.0.363.10&idno=14 FARs require] the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the [http://www.aircraftspruce.com/catalog/hapages/an818.php AN 818-4D] line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an AN 806-4D plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the Cleveland Wheel and Brake Parts Catalog for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on bleeding the brakes for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T23:09:25Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=794f31fd6027b03033374ec96690b9fe&rgn=div8&view=text&node=14:1.0.1.3.20.0.363.10&idno=14 FARs require] the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the AN 818-4D line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an AN 806-4D plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the Cleveland Wheel and Brake Parts Catalog for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on bleeding the brakes for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T23:00:09Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The [http://www.parker.com/ag/wbd/cleveland/pdf/maincov.pdf Cleveland Wheel and Brake Maintenance Manual] is available on-line. The FARs require the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the AN 818-4D line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an AN 806-4D plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the Cleveland Wheel and Brake Parts Catalog for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on bleeding the brakes for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T22:58:26Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The Cleveland Wheel and Brake Maintenance Manual is available on-line. The FARs require the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the AN 818-4D line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an AN 806-4D plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the Cleveland Wheel and Brake Parts Catalog for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on bleeding the brakes for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T22:56:59Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a Mil Spec fluid MIL-H-5606G, commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The Cleveland Wheel and Brake Maintenance Manual is available on-line. The FARs require the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [[Image:Wrench2.jpg]]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the AN 818-4D line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an AN 806-4D plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the Cleveland Wheel and Brake Parts Catalog for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on bleeding the brakes for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [[Image:wrench3.jpg]]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T22:55:55Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a Mil Spec fluid MIL-H-5606G, commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The Cleveland Wheel and Brake Maintenance Manual is available on-line. The FARs require the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

'''The Wheel Slave Cylinder'''

'''Mechanical Difficulty:''' [Image:Wrench2.jpg]

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the AN 818-4D line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an AN 806-4D plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the Cleveland Wheel and Brake Parts Catalog for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on bleeding the brakes for instructions on how to purge the air from the system.

'''The Master Cylinders'''

'''Mechanical Difficulty:''' [Image:wrench3.jpg]

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that

<TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T22:54:02Z

66.167.55.183:

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a Mil Spec fluid MIL-H-5606G, commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The Cleveland Wheel and Brake Maintenance Manual is available on-line. The FARs require the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

The Wheel Slave Cylinder

Mechanical Difficulty:Image:Wrench2.jpg

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the AN 818-4D line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an AN 806-4D plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the Cleveland Wheel and Brake Parts Catalog for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on bleeding the brakes for instructions on how to purge the air from the system.

The Master Cylinders

Mechanical Difficulty: Image:wrench3.jpg

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that <TO BE CONTINUED>

Brake Master and Slave Cylinders

2006-01-10T22:53:37Z

66.167.55.183:

== Cleaning, re-sealing and repairing Master and Slave cyinders ==
From Bondline

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

The hydraulic brakes use a Mil Spec fluid MIL-H-5606G, commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

If hydraulic fluid leaks have been found at the brake caliper on either main wheel, the likely causes are worn o-ring, pitted wheel cylinder or cracked wheel cylinder casting at the inlet or bleeder fitting.

The Cleveland Wheel and Brake Maintenance Manual is available on-line. The FARs require the use of the manufacturer's current maintenance instructions, and the Grumman maintenance manual gives very little detail about the wheel and brake system.

The Wheel Slave Cylinder

Mechanical Difficulty:Image:Wrench2.jpg

To remove the caliper the 1/4" bolts that hold the outer brake pad retaining plate in place must be removed. The inlet line should then be removed by untorquing the AN 818-4D line nut. The line nut should require no more than 1/8 turn with a wrench before being free enough to spin off with your fingers. If the threads require a wrench to loosen them further, careful inspection of the line nut and inlet fitting threads is in order.

As soon as the line nut is loosened, 5606 fluid will begin leaking out. A small catch pan is a good idea to prevent s spill and an unsafe condition with a slippery floor. A well prepared mechanic will have an AN 806-4D plug ready to seal the line and prevent losing all the fluid in that side of the brake system!

With the brake line removed the caliper can be pulled inboard and removed from the mounting bracket. Exploded views of the caliper can be found in the Cleveland Wheel and Brake Parts Catalog for easy reference to part numbers and assembly details.

With the caliper off the mounting bracket, slide the inner brake pad and backing plate off the mounting pins and remove the piston. A common method is to wrap the caliper assembly in a rag and apply air pressure to the inlet fitting to drive the piston out of the bore. There is a small amount of fluid that remains in the caliper and eye protection is suggested to prevent a chemical irritation should the remaining fluid spray in the direction of your face.

After the piston is removed, a thorough cleaning of the caliper housing and piston is next. A solvent rinse (mineral spirits or an automotive style "brake cleaner") to degrease, followed by soap and water with a mild abrasive like Scotch-Brite to remove stubborn dirt and oxidation, completed by a fresh water rinse and air drying should be sufficient to allow a good inspection.

Evidence of pitting in the caliper bore is quite common on older components, especially those that have been operated in a corrosive environment. Of the pitting is very light, and only at the outer edges of the bore, it may not cause a leak under normal circumstances. The o-ring that seals the piston to the caliper bore is set back from the edge of the piston, so the actual seal takes place deeper in the bore. However as the brake pads and the rotor wear, the piston can move further out and reach a point where the o-ring may leak.

The minimum thickness of the rotor and the minimum thickness of the brake pads are designed such that the piston will not travel too far out of the bore when the minimum thicknesses are reached, and the o-ring will still seal if the bore is in good shape. Allowing the brakes to deteriorate past the point of the recommended minimum thickness can cause the piston to move far enough that the o-ring pops out of the caliper bore, and all brake effectiveness is lost without warning.

After cleaning and inspecting the caliper and piston, I suggest an acid etch and alodine, just like the pre-treatment of structural aluminum in preparation for painting. A coat of zinc chromate or an epoxy primer on the external surfaces, followed by a color coat to protect against future corrosion would be a good idea. The caliper has a data plate on it that identifies the manufacturer (Cleveland), the model and other info like the date of production (month and year) in most cases. If the data plate is missing or unreadable, then the part is technically unairworthy. The good news is, that if you contact Cleveland support at the number in the on line manuals, that you can ask nicely for replacement data plates, and they will send them to you AT NO CHARGE. The current production data plates are laser printed on a plastic based label, and just peel off and attach to a clean, smooth surface.

After all the surface prep, primer and paint, the caliper is ready to assemble. Install a new O-ring and lube it and the bore of the caliper with a generous amount of 5606 fluid, and insert the piston with a rotating motion. Once lined up correctly, it will slide into place with a quick motion and be ready to wipe off and install on the plane.

Refer to the section on bleeding the brakes for instructions on how to purge the air from the system.

The Master Cylinders

Mechanical Difficulty: Image:wrench3.jpg

On most Grummans there are 4 Master Cylinders, a pair for each pilot. They are plumbed such that <TO BE CONTINUED>

Brake System

2006-01-10T22:52:55Z

66.167.55.183:

* [[== Fixing soft brakes caused by fluid leaks and air in the system ==]]

* [[== Cleaning, re-sealing and repairing Master and Slave cylinders ==]]

* [[== Cleaning, re-sealing and repairing Master and Slave cyinders ==]]

Brake System

2006-01-10T22:49:33Z

66.167.55.183:

* [[== Fixing soft brakes caused by fluid leaks and air in the system ==]]

* [[== Cleaning, re-sealing and repairing Master and Slave cylinders ==]]

User:Bob Steward

2006-01-09T00:08:58Z

66.167.55.183:

Bob Steward is a Grumman owner for 20 years (Jan 86), a private pilot with Seaplane and Glider ratings, an aircraft mechanic with an Inspection Authorization, [http://www.aya.org/star/search/?q=Bob+Steward&n=50 a frequent contributor to the AYA Star] and an active [http://www.eaa.org EAA member] with several [http://home.mindspring.com/~n76lima/n624bd/ homebuilt projects].

User:Bob Steward

2006-01-09T00:08:21Z

66.167.55.183:

Bob Steward is a Grumman owner for 20 years (Jan 86), a private pilot with Seaplane and Glider ratings, an aircraft mechanic with an Inspection Authorization, [http://www.aya.org/star/search/?q=Bob+Steward&n=50 a frequent contributor to the AYA Star] and an active [www.eaa.org EAA member] with several [http://home.mindspring.com/~n76lima/n624bd/ homebuilt projects].

Fixing Soft Brakes

2006-01-08T23:33:46Z

66.167.55.183:

Mechanical Difficulty: [[Image:Wrench2.jpg]]

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

Although the brake system on Grumman American singles is listed in the parts manual and sales brochures as having "optional" passenger side brakes, few seem to have been built with the "standard" brakes. Accordingly, I'll discuss the brake system as if they ALL have brake pedals on both sides.

Due to the way the pilot's side master cylinders plumb through the co-pilot's side master cylinders, if the fluid is too low in the reservoir(s), the pilot's side brake pedal(s) can be soft and ineffective, and the co-pilot's side can still operate normally -- but perhaps only for a few applications, depending on the size of the leak. This can be used to your advantage if the brakes are checked as part of a pre-landing checklist (step on the toe brakes in flight and see if either is soft) by giving you advance warning of the loss of brake effectiveness and allowing you to either change seats if solo, or to transfer braking responsibilty to the co-pilot.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

The pilot's side master cylinders each have built-in reservoirs that contain the surplus fluid needed as the brake pads wear and the wheel cylinder piston moves out to take up the missing pad thickness. The proper fill level is approximately 1/4" below the top of the reservoir, and can be measured with a pipe cleaner. Filling the system before the fluid level drops far enough to suck in air will prevent the loss of braking and subsequently, directional control on the ground.

When air enters the brake system, the brake pedals become mushy, soft, and ineffective. When this occurs, the air must be replaced with brake fluid by "bleeding" the brakes. The brakes are bled by pumping clean 5606 fluid into the bottom bleeder valve on the brake cylinder located on the inboard aft side of each main wheel. A 1/4" box end wrench is needed to loosen the bleeder. Note: Many people get confused about the direction to turn the bleeder screw, since it is upside down.

The best way to force fluid into the system is by using a pistol-grip style oil can with a short section of clear plastic line slipped over the tip. The vinyl line used on aquarium air systems works well, as does certain types of surgical rubber tube. Prepare for servicing the brakes by filling the oil can with several ounces of 5606 fluid and by attaching the flex hose to the end of the can. Finally, pump the flexible hose full of brake fluid to avoid pumping air bubbles INTO the system.

You're now ready to begin the bleeding procedure, which is greatly simplified by having a second person in the cockpit to monitor its progress.

Remove the filler plug from the master cylinder reservoir on the correct side of the brake system, and then put your 1/4" box end wrench on the bleeder fitting and crack it open. You'll know you've opened the fitting when a drop of fluid appears. While leaving the wrench on the bleeder hex-screw, slip the end of the preloaded flex hose over the end of the bleeder screw, loosen the bleeder screw an additional half-turn, and begin pumping enough to purge the air from the lines. My hand pump oil usually takes 15-20 strokes to accomplish this.

Now, tighten the bleeder snugly--but leave the hose attached. Check the pedal on the pilot's side; if it's firm, then you can stop pumping. If not, open bleeder and continue pumping and checking until the pedal is firm.

After bleeding the brakes, check the fluid level with a pipe cleaner to make certain that it's within 1/4" of the top of the reservoir. If the fluid is lower, bring your pump inside and fill the reservoir. Re-install the filler plug when done.

In addition to loss of brake fluid, there are many reasons why the brake pedal might become soft. A history of fluid loss requires a careful inspection of the brake masters, the flex lines in the cockpit, the hard lines in the cockpit, and especially the aluminum hard lines from the wing walk area to the wheel cylinders. Cracks in the flare of the aluminum tube where it enters the caliper are very common, especially on the older members of the fleet. The entire line can be replaced with a new part from FletchAir or one fabricated in the field from [http://www.aircraftspruce.com/catalog/mepages/alumtube_5052.php 5052-O aluminum tube (0.035" wall)] or many have been repaired with a [http://www.aircraftspruce.com/catalog/appages/aq666.php 6" section of teflon lined steel braided hose] and a [http://www.aircraftspruce.com/catalog/hapages/an815.php straight union AN fitting] to couple the re-flared line to the female flex hose.

Due to a change in the parking brake design on some '78 and all '79 and later 4-place, a rather baffling loss of fluid can occur. The fluid can disappear from one master cylinder reservoir, and over fill the other! The parking brakes are plumbed with a [http://www.aircraftspruce.com/catalog/lgpages/pbvalves.php valve] that can be closed to hold braking pressure after the pedals are released, and the o-rings in the valve are known to fail such that the pressure is leaked from one half the system to the other side with no external leaking. The fix is to remove the parking brake valve from the firewall ahead of the co-pilot's rudder pedals and repair it with a new set of o-rings.

Fixing Soft Brakes

2006-01-08T23:32:33Z

66.167.55.183:

Mechanical Difficulty: [[Image:Wrench2.jpg]]

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

Although the brake system on Grumman American singles is listed in the parts manual and sales brochures as having "optional" passenger side brakes, few seem to have been built with the "standard" brakes. Accordingly, I'll discuss the brake system as if they ALL have brake pedals on both sides.

Due to the way the pilot's side master cylinders plumb through the co-pilot's side master cylinders, if the fluid is too low in the reservoir(s), the pilot's side brake pedal(s) can be soft and ineffective, and the co-pilot's side can still operate normally -- but perhaps only for a few applications, depending on the size of the leak. This can be used to your advantage if the brakes are checked as part of a pre-landing checklist (step on the toe brakes in flight and see if either is soft) by giving you advance warning of the loss of brake effectiveness and allowing you to either change seats if solo, or to transfer braking responsibilty to the co-pilot.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

The pilot's side master cylinders each have built-in reservoirs that contain the surplus fluid needed as the brake pads wear and the wheel cylinder piston moves out to take up the missing pad thickness. The proper fill level is approximately 1/4" below the top of the reservoir, and can be measured with a pipe cleaner. Filling the system before the fluid level drops far enough to suck in air will prevent the loss of braking and subsequently, directional control on the ground.

When air enters the brake system, the brake pedals become mushy, soft, and ineffective. When this occurs, the air must be replaced with brake fluid by "bleeding" the brakes. The brakes are bled by pumping clean 5606 fluid into the bottom bleeder valve on the brake cylinder located on the inboard aft side of each main wheel. A 1/4" box end wrench is needed to loosen the bleeder. Note: Many people get confused about the direction to turn the bleeder screw, since it is upside down.

The best way to force fluid into the system is by using a pistol-grip style oil can with a short section of clear plastic line slipped over the tip. The vinyl line used on aquarium air systems works well, as does certain types of surgical rubber tube. Prepare for servicing the brakes by filling the oil can with several ounces of 5606 fluid and by attaching the flex hose to the end of the can. Finally, pump the flexible hose full of brake fluid to avoid pumping air bubbles INTO the system.

You're now ready to begin the bleeding procedure, which is greatly simplified by having a second person in the cockpit to monitor its progress.

Remove the filler plug from the master cylinder reservoir on the correct side of the brake system, and then put your 1/4" box end wrench on the bleeder fitting and crack it open. You'll know you've opened the fitting when a drop of fluid appears. While leaving the wrench on the bleeder hex-screw, slip the end of the preloaded flex hose over the end of the bleeder screw, loosen the bleeder screw an additional half-turn, and begin pumping enough to purge the air from the lines. My hand pump oil usually takes 15-20 strokes to accomplish this.

Now, tighten the bleeder snugly--but leave the hose attached. Check the pedal on the pilot's side; if it's firm, then you can stop pumping. If not, open bleeder and continue pumping and checking until the pedal is firm.

After bleeding the brakes, check the fluid level with a pipe cleaner to make certain that it's within 1/4" of the top of the reservoir. If the fluid is lower, bring your pump inside and fill the reservoir. Re-install the filler plug when done.

In addition to loss of brake fluid, there are many reasons why the brake pedal might become soft. A history of fluid loss requires a careful inspection of the brake masters, the flex lines in the cockpit, the hard lines in the cockpit, and especially the aluminum hard lines from the wing walk area to the wheel cylinders. Cracks in the flare of the aluminum tube where it enters the caliper are very common, especially on the older members of the fleet. The entire line can be replaced with a new part from FletchAir or one fabricated in the field from [http://www.aircraftspruce.com/catalog/mepages/alumtube_5052.php 5052-O aluminum tube (0.035" wall)] or many have been repaired with a [http://www.aircraftspruce.com/catalog/appages/aq666.php 6" section of teflon lined steel braided hose] and a [http://www.aircraftspruce.com/catalog/hapages/an815.php straight union AN fitting] to couple the re-flared line to the female flex hose.

Due to a change in the parking brake design on some '78 and all '79 and later 4-place, a rather baffling loss of fluid can occur. The fluid can disappear from one master cylinder reservoir, and over fill the other! The parking brakes are plumbed with a valve that can be closed to hold braking pressure after the pedals are released, and the o-rings in the valve are known to fail such that the pressure is leaked from one half the system to the other side with no external leaking. The fix is to remove the parking brake valve from the firewall ahead of the co-pilot's rudder pedals and repair it with a new set of o-rings.

Fixing Soft Brakes

2006-01-08T23:30:38Z

66.167.55.183:

Mechanical Difficulty: [[Image:Wrench2.jpg]]

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

Although the brake system on Grumman American singles is listed in the parts manual and sales brochures as having "optional" passenger side brakes, few seem to have been built with the "standard" brakes. Accordingly, I'll discuss the brake system as if they ALL have brake pedals on both sides.

Due to the way the pilot's side master cylinders plumb through the co-pilot's side master cylinders, if the fluid is too low in the reservoir(s), the pilot's side brake pedal(s) can be soft and ineffective, and the co-pilot's side can still operate normally -- but perhaps only for a few applications, depending on the size of the leak. This can be used to your advantage if the brakes are checked as part of a pre-landing checklist (step on the toe brakes in flight and see if either is soft) by giving you advance warning of the loss of brake effectiveness and allowing you to either change seats if solo, or to transfer braking responsibilty to the co-pilot.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

The pilot's side master cylinders each have built-in reservoirs that contain the surplus fluid needed as the brake pads wear and the wheel cylinder piston moves out to take up the missing pad thickness. The proper fill level is approximately 1/4" below the top of the reservoir, and can be measured with a pipe cleaner. Filling the system before the fluid level drops far enough to suck in air will prevent the loss of braking and subsequently, directional control on the ground.

When air enters the brake system, the brake pedals become mushy, soft, and ineffective. When this occurs, the air must be replaced with brake fluid by "bleeding" the brakes. The brakes are bled by pumping clean 5606 fluid into the bottom bleeder valve on the brake cylinder located on the inboard aft side of each main wheel. A 1/4" box end wrench is needed to loosen the bleeder. Note: Many people get confused about the direction to turn the bleeder screw, since it is upside down.

The best way to force fluid into the system is by using a pistol-grip style oil can with a short section of clear plastic line slipped over the tip. The vinyl line used on aquarium air systems works well, as does certain types of surgical rubber tube. Prepare for servicing the brakes by filling the oil can with several ounces of 5606 fluid and by attaching the flex hose to the end of the can. Finally, pump the flexible hose full of brake fluid to avoid pumping air bubbles INTO the system.

You're now ready to begin the bleeding procedure, which is greatly simplified by having a second person in the cockpit to monitor its progress.

Remove the filler plug from the master cylinder reservoir on the correct side of the brake system, and then put your 1/4" box end wrench on the bleeder fitting and crack it open. You'll know you've opened the fitting when a drop of fluid appears. While leaving the wrench on the bleeder hex-screw, slip the end of the preloaded flex hose over the end of the bleeder screw, loosen the bleeder screw an additional half-turn, and begin pumping enough to purge the air from the lines. My hand pump oil usually takes 15-20 strokes to accomplish this.

Now, tighten the bleeder snugly--but leave the hose attached. Check the pedal on the pilot's side; if it's firm, then you can stop pumping. If not, open bleeder and continue pumping and checking until the pedal is firm.

After bleeding the brakes, check the fluid level with a pipe cleaner to make certain that it's within 1/4" of the top of the reservoir. If the fluid is lower, bring your pump inside and fill the reservoir. Re-install the filler plug when done.

In addition to loss of brake fluid, there are many reasons why the brake pedal might become soft. A history of fluid loss requires a careful inspection of the brake masters, the flex lines in the cockpit, the hard lines in the cockpit, and especially the aluminum hard lines from the wing walk area to the wheel cylinders. Cracks in the flare of the aluminum tube where it enters the caliper are very common, especially on the older members of the fleet. The entire line can be replaced with a new part from FletchAir or one fabricated in the field from [http://www.aircraftspruce.com/catalog/mepages/alumtube_5052.php 5052-O aluminum tube (0.035" wall)] or many have been repaired with a 6" section of teflon lined steel braided hose and a [http://www.aircraftspruce.com/catalog/hapages/an815.php straight union AN fitting] to couple the re-flared line to the female flex hose.

Due to a change in the parking brake design on some '78 and all '79 and later 4-place, a rather baffling loss of fluid can occur. The fluid can disappear from one master cylinder reservoir, and over fill the other! The parking brakes are plumbed with a valve that can be closed to hold braking pressure after the pedals are released, and the o-rings in the valve are known to fail such that the pressure is leaked from one half the system to the other side with no external leaking. The fix is to remove the parking brake valve from the firewall ahead of the co-pilot's rudder pedals and repair it with a new set of o-rings.

Fixing Soft Brakes

2006-01-08T23:29:22Z

66.167.55.183:

Mechanical Difficulty: [[Image:Wrench2.jpg]]

[Bob Steward writes] Properly maintaining the brake system on Grumman American aircraft is extremely important because the brakes are the only way to steer the plane on the ground at low speeds where the rudder is ineffective.

Although the brake system on Grumman American singles is listed in the parts manual and sales brochures as having "optional" passenger side brakes, few seem to have been built with the "standard" brakes. Accordingly, I'll discuss the brake system as if they ALL have brake pedals on both sides.

Due to the way the pilot's side master cylinders plumb through the co-pilot's side master cylinders, if the fluid is too low in the reservoir(s), the pilot's side brake pedal(s) can be soft and ineffective, and the co-pilot's side can still operate normally -- but perhaps only for a few applications, depending on the size of the leak. This can be used to your advantage if the brakes are checked as part of a pre-landing checklist (step on the toe brakes in flight and see if either is soft) by giving you advance warning of the loss of brake effectiveness and allowing you to either change seats if solo, or to transfer braking responsibilty to the co-pilot.

The hydraulic brakes use a [http://www.aircraftspruce.com/catalog/lgpages/aeroshell_bflu.php Mil Spec fluid MIL-H-5606G], commonly referred to as "5606". This is a red petroleum-based fluid, as opposed to the Glycol based automotive fluids, and the system is not compatible with any other fluid.

The pilot's side master cylinders each have built-in reservoirs that contain the surplus fluid needed as the brake pads wear and the wheel cylinder piston moves out to take up the missing pad thickness. The proper fill level is approximately 1/4" below the top of the reservoir, and can be measured with a pipe cleaner. Filling the system before the fluid level drops far enough to suck in air will prevent the loss of braking and subsequently, directional control on the ground.

When air enters the brake system, the brake pedals become mushy, soft, and ineffective. When this occurs, the air must be replaced with brake fluid by "bleeding" the brakes. The brakes are bled by pumping clean 5606 fluid into the bottom bleeder valve on the brake cylinder located on the inboard aft side of each main wheel. A 1/4" box end wrench is needed to loosen the bleeder. Note: Many people get confused about the direction to turn the bleeder screw, since it is upside down.

The best way to force fluid into the system is by using a pistol-grip style oil can with a short section of clear plastic line slipped over the tip. The vinyl line used on aquarium air systems works well, as does certain types of surgical rubber tube. Prepare for servicing the brakes by filling the oil can with several ounces of 5606 fluid and by attaching the flex hose to the end of the can. Finally, pump the flexible hose full of brake fluid to avoid pumping air bubbles INTO the system.

You're now ready to begin the bleeding procedure, which is greatly simplified by having a second person in the cockpit to monitor its progress.

Remove the filler plug from the master cylinder reservoir on the correct side of the brake system, and then put your 1/4" box end wrench on the bleeder fitting and crack it open. You'll know you've opened the fitting when a drop of fluid appears. While leaving the wrench on the bleeder hex-screw, slip the end of the preloaded flex hose over the end of the bleeder screw, loosen the bleeder screw an additional half-turn, and begin pumping enough to purge the air from the lines. My hand pump oil usually takes 15-20 strokes to accomplish this.

Now, tighten the bleeder snugly--but leave the hose attached. Check the pedal on the pilot's side; if it's firm, then you can stop pumping. If not, open bleeder and continue pumping and checking until the pedal is firm.

After bleeding the brakes, check the fluid level with a pipe cleaner to make certain that it's within 1/4" of the top of the reservoir. If the fluid is lower, bring your pump inside and fill the reservoir. Re-install the filler plug when done.

In addition to loss of brake fluid, there are many reasons why the brake pedal might become soft. A history of fluid loss requires a careful inspection of the brake masters, the flex lines in the cockpit, the hard lines in the cockpit, and especially the aluminum hard lines from the wing walk area to the wheel cylinders. Cracks in the flare of the aluminum tube where it enters the caliper are very common, especially on the older members of the fleet. The entire line can be replaced with a new part from FletchAir or one fabricated in the field from [http://www.aircraftspruce.com/catalog/mepages/alumtube_5052.php 5052-O aluminum tube (0.035" wall)] or many have been repaired with a 6" section of teflon lined steel braided hose and a straight union AN fitting to couple the re-flared line to the female flex hose.

Due to a change in the parking brake design on some '78 and all '79 and later 4-place, a rather baffling loss of fluid can occur. The fluid can disappear from one master cylinder reservoir, and over fill the other! The parking brakes are plumbed with a valve that can be closed to hold braking pressure after the pedals are released, and the o-rings in the valve are known to fail such that the pressure is leaked from one half the system to the other side with no external leaking. The fix is to remove the parking brake valve from the firewall ahead of the co-pilot's rudder pedals and repair it with a new set of o-rings.