SUPPORT GP-CYL 1723855 - Caterpillar

Steel Plates
Inspect the steel plates for thickness, scored surfaces, radial grooves or for being warped. Replace the plates if any of the following conditions exist.1. If plates are less than .085 in. (2.16 mm) thick.2. Has greater than 10% of the surface area scored.3. If the plates has deep radial grooves that would act as a cutting edge on the friction material on other discs.4. If the plate is warped and cannot be flattened with a force of 20 pounds (9.07 kg).Damper Plate Assemblies
Inspect the cork plate assembly for thickness and condition of bonding material. Replace the plate if any of the following conditions exist.1. If the thickness of the plate is .200 in. (5.1 mm) or less.2. If there is a bonding failure between the cork material and the steel backing plate.Total Brake Pack Clearance
The total brake pack clearance (damper plate assemblies, steel reaction plates and friction discs) should be checked after the individual parts have been measured.
769 Truck and 768 Tractor MEASUREMENT (A)
A. Measurement from top of gear to face of plate.Add steel reaction plates between the damper plate assembly and the adjacent friction discs at either end of the brake pack to get a pack clearance (brake piston stroke) of .125 in. (3.18 mm) to .220 in. (5.59 mm). The brake piston stroke is the difference in measurements (A) and (B). Do not add more than three steel reaction plates to any brake pack to reduce the clearance to the above specified measurements. All plates must be clean. Do not use plates with rust on them.
769 Truck and 768 Tractor MEASUREMENT (B)
B. Measurement from face of spindle to face of piston.
773 Truck and 772 Tractor MEASUREMENT (A)
A. Measurement from face of housing to face of plate.
773 Truck and 772 Tractor MEASUREMENT (B)
B. Measurement from face of anchor assembly to face of piston.After any disassembly of the brake pack, recheck the master cylinder stroke to assure the repairs have corrected the deficiencies. If the master cylinder stroke is less than 1 in. (25.4 mm), (769 Truck 99F1031-99F1040, 768 Tractor 79S1-79S79, 773 Truck 63G1-63G70 and 772 Tractor 80S1-80S54) or 1.60 in. (40.7 mm), (769 Truck 99F3741-UP, 768 Tractor 79S80-UP, 773 Truck 63G71-UP and 772 Tractor 80S55-UP) excessive brake drag may occur. Therefore, it is important the various brake pack component measurements and the brake pack clearance measurements be carefully made and it is equally important to comply to the specific dimensions.A record of measurements at a particular SMU (Service Meter Unit) for later reference and comparison would be beneficial.Check For Failed Slack Adjuster
After checking for leakage in the brake master cylinders and brake piston seals, check for a failed slack adjuster. All checks must be made with air bled from the brake oil system, standard air system at operating pressure, brake OFF and engine stopped. The openings in the bleed screws, (located on top of each brake housing) must be free of dirt.1. Apply the brakes several times and measure the stroke of a master cylinder. If