BODY 6J4271 - Caterpillar

Service Brake Operation
Illustration 1 g06319446
Brake control manifold with accumulators at equal pressure, service brake applied.
(1) Brake Accumulator
(2) Service Brake Valve
(3) Left Park Brake
(4) Left Service Bake
(5) Right Service Brake
(6) Right Park Brake
(7) Return to Tank
(8) Park Brake Spool
(9) Piston Pump (Brake)
(10) Park Brake Solenoid
(11) Brake Release Motor/Pump (Tow Motor/Pump)
(12) Park Brake Pressure Sensor
(13) Service Brake Accumulator Pressure Sensor
(14) Service Brake Accumulator Shuttle ValveHydraulic oil enters the brake manifold (15) and flows to the accumulator shuttle valve (14). From valve (14) oil will be diverted to the accumulator (1) having the lowest oil pressure. From the accumulators (1) oil flows to service brake valve (2). When the brake pedal is depressed, brake valve (2) allows oil to flow to right service brake (5) and left service brake (4). When the brake pedal is allowed to return to normal position, the spring in service brake (4) and (5) will force oil from the brake and to tank return (7).Park Brake Operation
Illustration 2 g06319446
Brake control manifold with parking brake released.
(1) Brake Accumulator
(2) Service Brake Valve
(3) Left Park Brake
(4) Left Service Bake
(5) Right Service Brake
(6) Right Park Brake
(7) Return to Tank
(8) Park Brake Spool
(9) Piston Pump (Brake)
(10) Park Brake Solenoid Valve
(11) Secondary Brake Pump
(12) Park Brake Pressure Sensor
(13) Accumulator Pressure Sensor
(14) Accumulator Shuttle ValveWith the park brake switch in the "OFF" position the park brake solenoid (10) is energized, oil flows thought solenoid valve (10) the oil overcomes the pressure of the spring and shifts park brake spool (8). With park brake spool (8) shifted oil from accumulators (1) flows to park brake (3) and right park brake (6). The oil flow to park brakes (3) and (6) overcomes the spring pressure of the brake and releases the park brake.