SWITCH AS-ROCKER 1802562 - Caterpillar

Service Brake Controls
Illustration 1 g01037654
Brake Pedals (1) Left brake pedal. (2) Right brake pedal. (3) Lock bar.The left brake pedal (1) controls the left service brake control valve and the left rear brakes. The right brake pedal (2) controls the right service brake control valve and the right rear brakes. The left and right brake pedals are connected together by the lock bar (3). The lock bar (3) allows both brake pedals to be applied together.Unlock the lock bar (3) to aid in maneuvering in tight quarters. Unlock the lock bar (3) in first gear only. Use the brake pedals with the steering wheel in order to make sharp turns. Use the left brake pedal to help with sharp left turns. Use the right brake pedal to help with sharp right turns.The brake pedal travel determines the force that is exerted by the brakes. The braking force increases as the travel of the brake pedal increases.Accumulator
Illustration 2 g01037659
The accumulator is located on the inside of the left frame rail behind the rear axle. The accumulator is a bladder which is in a precharged state with nitrogen to 8300 kPa (1204 psi). The accumulator stores pressure oil for the brake system in order to be used by the brake control valve. The accumulator provides a sufficient quantity of pressurized oil in order to stop the vehicle in the event of a pump supply oil loss.Brake control Valve
Illustration 3 g01037499
(1) Selector spool for the Left Brake (2) Tank Passage (3) Ports for the Brake Cylinder (4) Pressure Passages (5) Pressure Regulating Spool (6) Tank Port (7) Pressure Port for the Brake Hydraulic System (8) Spring Cavity (9) Selector spool for the Right BrakeThe brake control valve is located behind a floorplate. The brake control valve and the mounting bracket are fastened together at the floorplate. Depressing the brake pedal brings the pedal in contact with the brake control valve spools.Pressure Regulating Spool (5) and Selector spools (1) and (9) are activated when the brake pedal is depressed. When Pressure Regulating Spool (5) is activated, oil from the Pressure Port for the Brake Hydraulic System (7) flows through Pressure Regulating Spool (5). The oil enters Spring Cavity (8) and pressure passages (4). As the selector spools (1) and (9) are activated, pressure oil goes from the pressure passages (4) around spools (1) and (9). Then, the oil flows to the brake cylinder ports (3) .When the brake pedal is not depressed, the brake cylinder ports (3) are vented to the tank around spools (1) and (9). The oil flows to tank passages (2), and then to tank port (6). The pressure oil in the brake hydraulic system is blocked at port (7) .Brake Cylinder
Illustration 4 g01037623
The left and the right brake cylinders are located on the rear axle, on either side of the differential. The cylinders receive pressurized oil from the brake control valve. When the brake cylinders are activated, piston (10) extends. The piston retracts the actuator rod (11) from the rear axle housing.