WINDOW GP 3637443 - Caterpillar

Block the machine to prevent movement before releasing the brakes. The machine can roll free if it is not blocked.
Manual Release of the Parking Brake
When insufficient oil pressure prevents disengagement of the parking brake with the parking and secondary brake control, the parking brake can be manually disengaged.
Block the wheels securely in order to prevent the machine from moving.Note: When the engine is shut off and the parking brake is manually released, only the wheel blocks prevent the machine from moving.
Illustration 1 g00695554
To disengage the parking brake, rotate adjusting screw (1) counterclockwise until slack adjuster (2) is backed off and there is no contact between the brake lining and the brake disc.If the machine malfunctions and the parking brake is manually disengaged, do not remove the wheel blocks until repairs have been carried out. Do not operate the machine until the parking brake has been reset.If the parking brake is manually disengaged for towing purposes, do not remove the wheel blocks until the machine has been connected to the towing machine. You must be sure that the towing machine will hold the machine.Resetting the Parking Brake
When service work is complete, rotate adjusting screw (1) clockwise until the brake lining contacts the brake disc.
Illustration 2 g00698198
Disconnect pressure switch (3) from the machine harness.
Start the engine.
Engage and then disengage the parking and secondary brake control at 10 second intervals 25 to 30 times. The slack adjuster will start to automatically adjust and the hydraulic system for the parking brake will automatically purge the system free of air.
When step 4 has been carried out leave the parking and secondary brake control in the DISENGAGED position.
Illustration 3 g00708660
Push spring brake actuator (4) and the parking brake forward toward the front of the machine.
Use a feeler gauge to measure the distance (A) between brake lining (5) and brake disc (6). The measured distance should be 0.7 to 1.1 mm (0.027 to 0.043 inch).Note: If the measured distance is not within the specified range check the operation of the slack adjuster and related parts.
Move the parking and secondary brake control to the ENGAGED position and stop the engine.
Reconnect pressure switch (3) to the machine harness.
For information on testing the parking brake, refer to Operation and Maintenance Manual, SEBU7064, "Braking System - Test".