VALVE MECHANISM GP 7W7485 - Caterpillar

Introduction
This information includes the following adjustment procedure:
Parking Brake Actuator - AdjustRequired Tools
Table 2
Required Tools    
Part Number     Description    
8H-8581     Feeler Gauge    Adjustment Preparation
ReferenceDisassembly and Assembly, "Parking Brake - Remove and Install".
Park the machine on a smooth, level surface.
Place the transmission control in the NEUTRAL position.
Lower the bucket and/or any work tools to the ground.
Engage the parking brake.
Shut off the engine.
Place blocks in front of the wheels and behind the wheels.
Illustration 1 g03122476
Steering Frame Lock
Install the steering frame lock.
Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.
Disengage the parking brake.
Remove the parking brake. The parking brake must be disassembled in order to perform the adjustment procedure.ReferenceFor information on removing and disassembling the parking brake, refer to Disassembly and Assembly, "Parking Brake - Remove and Install".Note: Be sure to avoid getting any grease or dirt on the brake shoes. Grease and dirt on the brake shoes greatly reduces the effectiveness of the parking brake.Adjustment Procedure for Disassembled Parking Brake
Illustration 2 g02718106
View of Parking Brake and Parking Brake Group
Illustration 3 g02717948
Illustration 4 g02717969
(2) Brake camshaft (3) Brake drum (4) Starwheel (5) Brake shoes (6) Brake group
Place brake group (6) into the brake drum (3) .
Rotate starwheel (4) in order to move brake shoes (5) outward. Rotate the starwheel until the brake shoes contact brake drum (2). Make sure that the brake shoes stay above the radius at the bottom of the brake drum.
Rotate starwheel (4) so that the brake shoes (5) press against brake drum (3) .
Rotate the starwheel (4) for 12 clicks in order to release the pressure of the brake shoes (5) on the brake drum (3) .
Pressurize the actuator to extend the actuator rod. The pressure should be 12500 to 15000 kPa (1800 to 2200 psi). Do not exceed the maximum pressure of 25000 kPa (3600 psi).
Illustration 5 g02718919
(7) Actuator shaft (8) Locknut (9) Rod end
Illustration 6 g02718961
(A) 150 mm (6 inch) (B) 30 - 50 mm (1.2 - 2 inch)
Adjust rod end (9) to obtain dimension (A) of 150 mm (6 inch). Do not torque locknut (8) .
Illustration 7 g02718110
View of Parking Brake and Actuator (10) Cotter pin (11) Clevis Pin (12) Lever (13) Splined end of brake camshaft (14) Bolt
Position lever (12) on the splined end of camshaft (13). Push lever (12) lightly by hand to take slack out of the system. Do not extend the brake shoes out to the drum. Align the hole in lever (12) with hole in rod end (9) .
Secure lever (12) on camshaft (13) with bolt (14). Install pin (11), washer, and cotter (10). Tighten locknut (8) on actuator shaft (7) .
Apply brake by releasing the hydraulic pressure in the actuator. Measure the length of the actuator stroke (B), refer to Illustration 6. Length (B) should be within 30 - 50 mm (1.2 - 2 inch). If the stroke is within these limits, the brake adjustment is complete. If the stroke is outside these limits, proceed to Step 10.
Verify that