PLATFORM GP-OPERATOR 3974537 - Caterpillar

Illustration 1 g01260707
Parking brake valve (1) Parking brake solenoid valve (2) Purge solenoid valve (3) Port for pressure switch (4) Port for parking brake oil (5) Inlet for pressurized oil from brake accumulator (6) Outlet to hydraulic tankThe parking brake valve is located on the outside right frame rail behind the middle crossmember.Pressurized oil flows from the parking brake accumulator to port (5) on the parking brake valve. When the parking brake solenoid valve (1) is energized, brake oil is allowed to move a valve that allows pressurized brake oil to flow through port (4) to the traction control valve, and to the rear parking brakes.Note: There are no parking brakes on the front wheels.When the machine is shut down, the purge solenoid (2) is energized, and the purge valve drains the brake accumulators to the hydraulic tank through port (6) .The parking brake pressure switch that is in port (3) monitors the pressure at the parking brakes.