CLAMP-HOSE 4989852 - Caterpillar

Illustration 1 g00905175
(1) Hydraulic tank (2) Implement pump (3) Combination valve (4) Steering pilot valve (5) Front differential lock (6) Rear differential lock (7) Parking brake pressure switch (8) Speed control valve (9) Parking brake (10) Forward pressure switch (11) Travel pedals (12) Steering cylinders (13) Reverse pressure switch (14) Pilot oil accumulator (15) Grapple pedals (16) Lift and tilt pilot valve (17) Implement control valve (18) Shear cylinders (if equipped) (19) Tilt cylinders (20) Lift cylinders (21) Collector arm cylinders (22) Grapple arm cylinders (AA) Pressure tap (pilot accumulator) (BB) Pressure tap (front differential lock) (CC) Pressure tap (pilot supply) (DD) Pressure tap (rear differential lock) (EE) Pressure tap (parking brake) (FF) Pressure tap (creeper speed) (GG) Pump pressure oil (HH) Return oil (II) Case drain oil (XX) Pilot line for creeper speed (YY) Pilot line (forward drive) (ZZ) Pilot line (reverse drive)The pilot hydraulic system receives oil flow from the implement pump. The pilot hydraulic system controls the following functions:
Illustration 2 g00858854
Partial Schematic of the Implement Control Valve (Collector Arm Cylinders) (23) Orifice (24) Proportional solenoids (25) Line relief valves (26) Pilot oil screen (27) Signal limiter valves (28) Check valve (29) Pilot relief valve (30) Stabilizer valve (31) Orifice (32) Pilot valve (33) Inlet section (34) Pressure compensator valve (35) Orifice (36) Spool (37) Collector arm section (38) Resolver (39) End section (A) Collector arms (CLOSE) (B) Collector arms (OPEN) (P1) Inlet from pump (P2) Pressure port (PL) Signal port to implement pump (PS) Pressure tap (T1) Return to tank
The pilot hydraulic system controls the operation of the implement control valve.When the engine is running, implement pump pressure flows to combination valve (3) and implement control valve (17). Pilot valve (32) in the implement control valve reduces the implement pump pressure to pilot pressure. Pilot valve (32) reduces the pressure oil to approximately 3500 kPa (510 psi).Note: The pilot pressure setting in the implement control valve is not adjustable.The pilot pressure oil flows through check valve (28) to pilot oil screen (26). If the screen becomes plugged, oil will flow through the bypass valve for the screen. The oil then flows to the two proportional solenoids (24) in the implement control valve. Check valve (28) allows the pressure in the pilot circuit to be maintained when the pump pressure suddenly decreases or the engine is stopped.Pilot relief valve (29) limits the maximum pressure to the pilot circuit.
Illustration 3 g00858864
Hydraulic lockout control (40) LOCKED position. (41) UNLOCKED position.
Illustration 4 g01084449
Partial Schematic of the Combination Valve (5) Front differential lock (6) Rear differential lock (7) Parking brake pressure switch (42) Pilot on/off solenoid valve (43) Check valve (44) Pilot pressure reducing valve (45) Differential lock solenoid valve (front) (46) Differential lock solenoid valve (rear) (47) Parking brake solenoid valve (48) Creeper speed solenoid valve (AA) Pressure tap (pilot accumulator) (BB) Pressure tap (front differential lock) (CC) Pressure tap (pilot supply) (DD) Pressure tap (rear differential lock) (EE) Pressure tap (parking brake) (FF) Pressure tap (creeper speed) (LO SPD) Pilot pressure for