WHEEL-STEERING 8R8438 - Caterpillar

When the parking brakes are released manually, the machine has no brakes.To avoid possible personal injury, the tires must be blocked securely before the parking brakes are manually released.
The parking brake can be released manually when insufficient pressure in the braking system prevents the parking brake from being released with the parking brake control.The machine must be parked on a level surface before the parking brake is manually released.
Block the wheels in order to prevent the machine from moving when the parking brake is released.
Install the steering frame lock. Refer to Operation and Maintenance Manual, "Steering Frame Lock".
Illustration 1 g01041381
Raise the dump body in order to access the parking brake actuator. If the dump body cannot be raised, access to the parking brake actuator can be gained from a position underneath the machine. Note: Install the body prop if the dump body is raised.
Illustration 2 g01130524
Loosen rod (2) which is connected to yoke (1). Rotate rod (2) clockwise. This allows a parking brake lever to move. This relieves the pressure from the brake pads. Rotate the shaft until the brake pads do not contact disc (1) and the parking brake has been released.Adjusting the Parking Brake
Note: The machine must be fully operational before the parking brake can be set.
Raise the body enough to lift the body prop and then move the hoist control to the HOLD position.
Lift the body prop.
Move the hoist control to the FLOAT position. This will allow the body to lower slowly until the weight of the body is supported by the body prop.
Fully screw rod (2) onto yoke (1).
Start the engine and move the parking brake control to the DISENGAGED position.
Illustration 3 g01130535
Remove plug (4) and the gasket. Insert a 6mm hexagonal drive into the hole and rotate the hexagonal drive clockwise until resistance is felt. The gap between the brake pads and the disc should now be zero.
To set the initial running clearance, rotate the hexagonal drive counterclockwise. You will feel a click on the hexagonal drive. Rotate the hexagonal drive for eight clicks.
Use a feeler gauge to check the gaps between the brake pads and the disc. The total running clearance between the disc and the brake pads should be 1.15 0.15 mm (0.045 0.006 inch).
If the running clearance is incorrect, increase or reduce the number of clicks. Refer to steps 6 through 8.
Install plug (4) and the gasket. Tighten the plug to a torque of 14 3 N m (10 2 lb ft).
Move the parking brake control to the ENGAGED position. Lower the body and shut off the engine.
Remove the blocks from the wheels and then remove the steering frame lock.