GOVERNOR GP 1436143 - Caterpillar

Illustration 3 g06035876
(15) Rear brake accumulator
(16) Front brake accumulator
(29) Transmission ECU
(T3) Front service brake pressure test port
(T4) Rear service brake pressure test port
Illustration 4 g06038657
Illustration 5 g06038672Accumulators (15) and (16) are located behind a panel on the right side of the cab. The front service brake pressure test port (T3). the rear service brake pressure test port (T4) and the transmission ECU (29) are located in the same area.Main Control Valve
Illustration 6 g03519317
Main control valve
(1) Piston pump
(9a) Pressure switch (service brake)
(9b) Pressure switch (service brake)
(12) Pressure switch (parking brake)
(26) Main combination valve
(T1) Brake pump discharge pressure test port
(T2) Service brake accumulator charge pressure test portMain control valve (1) is located beneath the cab and on the left side of the machine. Pressure switches (9a and 9b) and (12) are installed in the main combination valve. Test ports T1 and T2 are installed in the main combination valve.Service Brakes Disengaged
Illustration 7 g06036914
(1) Piston pump
(2) Pump cutoff spool
(3) Pump flow compensator spool
(4) Brake signal resolver
(5) Brake priority valve
(6) Signal resolver
(7) Brake charge control solenoid
(8) Service brake check valve
(9) Brake pressure sensors
(10) Parking brake check valve
(11) Park brake control solenoid
(12) Park brake pressure sensor
(13) Inverse resolver
(14) Park brake accumulator
(15) Rear service brake accumulator
(15A) Rear service brake accumulator
(16) Front service brake accumulator
(16A) Front service brake accumulator
(17) Rear brake pressure test port
(18) Front brake pressure test port
(19) Front axle service brake
(20) Park brake actuator
(21) Center axle service brakes
(22) Rear axle service brakes
(23) Hydraulic oil tank
(24) Main combination valve
(25) Brake control valve
(26) Parking brake switch
(27) Transmission ECM
(28) Rear service brake spool
(29) Front service brake spool
(T1) Brake pump discharge pressure test port
(T2) Service brake accumulator charge pressure test port
(T3) Front service brake pressure test port
(T4) Rear service brake pressure test portWhen the engine is started and the brake accumulators are discharged, the brake hydraulic system begins to charge the accumulators, if needed. The Brake Pressure Sensors (9a and 9b) are monitored by the Transmission ECM (27) and detect low brake pressure. The low brake pressure causes the ECM to keep the Brake Charge Control Solenoid (7) DE-ENERGIZED. In the DE-ENERGIZED state, the solenoid valve directs pump discharge pressure from the Piston Pump (1) into the signal resolver network. This signal pressure is transmitted through the Signal Resolver (4) and the Brake Signal Resolver (6) to the Flow Compensator Spool (3). The spool shifts to the LEFT, causing the pump to UPSTROKE. This signal pressure also closes the Brake Priority Valve (5) to ensure that the braking system gets oil priority over other systems. The pump discharge oil opens and flows through the Service Brake Check Valve (8) and then to the Inverse Resolver (13). The oil flows in both directions from the resolver to charge rear brake accumulator (15), rear brake accumulator (15A), front brake accumulator (16), and front brake accumulator (16A). The oil is also blocked by rear axle spool (28) and front axle spool (29). Since the service brakes are RELEASED by springs and ENGAGED by hydraulic pressure, the service brakes are RELEASED in this condition.When the service