COVER 2296868 - Caterpillar

Personal injury or death can result from machine movement.Place blocks in front of and behind the wheels to make sure the machine does not move while the parking brakes are disengaged.
An internal oil leak in the brake release system will cause the outlet pressure of the parking brake release pump to decrease. An internal oil leak can also cause too much friction between the brake discs and the plates. This can cause damage to the brake discs and the plates.
Check the brake release system for an internal leak.
Illustration 1 g00331294
(1) Oil line that is connected to the TCS valve
(2) Brake control valve
Disconnect the oil line that is connected to the TCS valve at the parking and secondary brake control valve. The valve is located across from the hydraulic tank on the right side of the frame.
Install a gauge that has a capacity of 6890 kPa (1000 psi) pressure and either a gate valve or a needle valve. The valve and the gauge should be installed between the TCS valve and the brake control valve. Note: The gauge must be connected between the TCS valve and the valve that was installed in step 3. There must not be any oil leaks after the gauge and the valve have been installed.
Start the engine. Operate the engine at high idle. High idle is 2310 50 rpm.
Move the transmission control lever to the NEUTRAL position. This will disengage the parking brake. Check the oil pressure that is shown on the gauge. The oil pressure should be 4300 350 kPa (630 50 psi). Note: If there is any oil leakage in the brake system, the gauge may not show a pressure of 4300 350 kPa (630 50 psi) .
Close the valve and look at the gauge. If the pressure has not decreased by 690 kPa (100 psi) after one minute, the brake release system will not be affected by the oil leakage. Perform the procedure that is in the Testing and Adjusting, "Parking Brake Release Pressure - Test" section of this service manual. Note: If the oil pressure in the brake release system decreases by 690 kPa (100 psi) or more after one minute, there is too much oil leakage and each component must be checked.
Illustration 2 g00331295
(5) Tube
Disconnect tube (5) from the right rear brake assembly.
Connect a gate valve or a needle valve to tube (5). Install a gauge that has a capacity of 6890 kPa (1000 psi) to the valve and the brake housing.
Start the engine. Operate the engine at high idle. High idle is 2310 50 rpm.
Move the parking brake control lever to the OFF position.
Close the valve that is connected to tube (5). Look at the gauge that is connected to the valve and the brake housing. If the oil pressure that is shown on the gauge decreases by 690 kPa (100 psi) in one minute, there is oil leakage in the brake assembly for the right wheel. If there is no drop in the