CYLINDER GP 1882894 - Caterpillar

Illustration 1 g01339203
Location of the service brake pedal (1) Service brake pedal
Illustration 2 g01339205
(1) Service brake pedal (2) Tank port for the front service brake (3) Brake port for the rear service brake (4) Brake port for the front service brake (5) Supply port for the front service brake (6) Supply port for the rear service brake (7) Tank port for the rear service brakeThe foot brake valve for the service brakes is located in the cab.The foot brake control for the service brake has separate ports for the front service brakes and the rear service brakes. The front service brakes may be locked out via the front brake lockout switch. the application of the service brake pedal results in braking by the rear brakes only. If the brakes are not locked out via the front brake lockout switch, the application of the service brake pedal will command the front and rear service brakes.Oil from the brake charge pump flows through the retarder control and service brake valve to the supply port for the front service brakes (5) and the supply port for the rear service brakes (6) of foot brake valve (1) .When the service brake control is depressed, internal passages in the foot brake valve route the supply oil to the port for the front service brakes (2) and to the port for the rear service brakes (3). This oil flows back through the retarder control and service brake valve to the rear slack adjuster. The oil flows from the slack adjuster in order to actuate the rear service brakes.When the service brake control is released, the oil that is returning through the service brake ports is routed to the hydraulic tank through the tank port for the front service brakes (2) and the tank port for the rear service brakes (7).