EXHAUST G 0340984 - Caterpillar

When the parking brakes are released manually, the machine has no brakes. To avoid possible personal injury, the tracks must be blocked securely before the parking brakes are manually released.
Chock the wheels.
Remove the rear belly guard.
If the engine or the fan/brake hydraulic system is inoperable, the machine will be unable to charge the brake accumulator that is used to release the park brake. Note: The machine must have battery power to allow the park brake to be disengaged. If the machine does not have battery power, supply 24 v power directly to the park brake solenoid to release the park brake.
Disengage the park brake switch.
Illustration 1 g03741049
(1) Park brake pressure test port
Illustration 2 g03741051
(2) Park brake solenoid
Install 1U-7544 Hand Pump to the park brake pressure test port (1). Note: If the 164-5567 Pressure Test Port and 7X-0872 Tee are not installed, install the tee fitting and pressure test port.
Pump the hand pump until pressure reads 4251 kPa (616 psi), which is the pressure required to retract the park brake.
Secure the hand pump in the cab to monitor the pressure so that the park brake does not reengage unexpectedly. The parking brake will release when there is sufficient pressure and voltage has been applied to the parking brake solenoid (2).