PUMP GP-PISTON & GEAR 2469876 - Caterpillar

Illustration 1 g01090551
Bowl Circuit in LOWER Position (1) Hydraulic tank (2) Vane pump (hydraulic and steering) (3) Main control valve (4) Pilot controlled actuator (bowl) (5) Pilot controlled actuator (bowl) (6) Pilot controlled actuator (apron) (7) Pilot controlled actuator (apron) (8) Pilot controlled actuator (ejector) (9) Pilot controlled actuator (ejector) (10) Solenoid and pressure reducing valve (11) Pilot oil filter (12) Shuttle valve (13) Cushion-hitch pump (14) Case drain screen for the cushion-hitch pump (15) Bowl cylinder (two) (16) Carry-check valve (two) (17) Check valve (two) (18) Line to cushion-hitch valve (19) Line to steering system (20) Ejector cylinder (21) Apron cylinder (22) Sequence valve (23) Snubber (24) Pressure switch (25) Main relief valve (26) Ball valve (27) Solenoid valve (pilot pressure supply) (28) Line from cushion-hitch pump (29) Shuttle valve (30) Pressure reducing valve (31) Pilot oil line (32) Valve spool (bowl) (33) Valve spool (ejector) (34) Valve spool (apron) (35) Line from main control valve to rod end of bowl cylinder (36) Line from main control valve to head end of bowl cylinder (37) Vent line from check valve (38) Line for equalization of bowl cylinders (39) Oil filter (40) Line from main control valve to the tank (41) Screen (42) Shuttle valve (43) Quick-drop valve (AA) Pressure oil from pump (BB) Return oil (CC) Blocked oil (DD) Pilot oilImplement pilot circuit
Illustration 2 g00760418
Joystick ControlWhen the engine is started with the joystick control in the HOLD position, the cushion-hitch pump (13) sends oil through line (28). Some of this oil flows through line (18) to the cushion-hitch valve. The rest of the oil flows through shuttle valve (12) and through screen (41) to solenoid and pressure reducing valve (10). Oil flows through solenoid valve (27) and pressure reducing valve (30) to filter (11). This oil flows through line (31) to main control valve (3). Regardless of the joystick movement, this is the pilot supply oil to the actuators for the following implements: the bowl, the apron and the ejector. Lowering the Bowl
When joystick control is moved to LOWER position, an electrical current is sent to the solenoid in actuator (5). This shifts valve spool (32) in order to lower the bowl. Pump oil flows around valve spool (32) and through line (36). Then, oil flows into the head ends of bowl cylinders (15). The oil pressure from the pump moves the pistons downward. This lowers the bowl. Oil from the spring cavity of valves (16) is vented to the tank through check valve (17). Rod end oil opens valves (16) and passes through the check valve group. This oil flows through line (35) to main control valve (3). The oil flows around valve spool (32) then through line (40), to filter (39) and to the tank (1) .When the joystick control is released, valve spool (32) will return to HOLD position. In HOLD position, oil is blocked in lines (35) and (36). Oil is also blocked in line (37) between the valve spool and check valves (17). Carry-check