BOX GP-STORAGE 3948001 - Caterpillar

Illustration 1 g01089192
Ejector in RETURN 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 (ejector) (7) Pilot controlled actuator (ejector) (8) Solenoid and pressure reducing valve (9) Pilot oil filter (10) Shuttle valve (11) Cushion-hitch pump (12) Case drain screen for the cushion-hitch pump (13) Bowl cylinder (two) (14) Carry-check valve (two) (15) Check valve (two) (16) Line to cushion-hitch valve (17) Line to steering system (18) Ejector cylinder (19) Floor cylinder (20) Check valve (floor) (21) Snubber (22) Pressure switch (23) Main relief valve (24) Ball valve (25) Solenoid valve (pilot pressure supply) (26) Line from cushion-hitch pump (27) Shuttle valve (28) Pressure reducing valve (29) Pilot oil line (30) Valve spool (bowl) (31) Valve spool (ejector) (32) Line from main control valve to rod end of ejector cylinder (33) Line from main control valve to head end of ejector cylinder (34) Vent line from check valve (35) Line for equalization of bowl cylinders (36) Oil filter (37) Line from main control valve to tank (38) Screen (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 (11) sends oil through line (26). Some of this oil flows through line (16) to the cushion-hitch valve. The rest of the oil flows through shuttle valve (10) and through screen (38) to solenoid and pressure reducing valve (8). Oil flows through solenoid valve (25) and pressure reducing valve (28) to filter (9). This oil flows through line (29) to main control valve (3). Regardless of the joystick movement, this is the pilot supply oil to the actuators for the bowl and the ejector.Ejector in the RETURN position
When the joystick control is moved to RETURN position, an electrical current is sent to the solenoid in actuator (6). This shifts spool (31) to RETURN position. The pump oil flows around the valve spool then through line (32) to the rod end of ejector cylinder (18). The pump oil in the rod end of ejector cylinder (18) moves the piston which pulls the ejector toward the retracted position in the bowl. The piston pushes oil from the head end of the ejector cylinder through line (33), around valve spool (31) and through line (37). This oil flows into filter (36) and hydraulic tank (1). At the same time, oil opens floor check valve (20) and flows into the head end of floor cylinder (19). The floor will move to CLOSED position. Then, oil from the rod end of floor cylinder (19) flows through line (33) and around valve spool (31). The oil flows through line (37), into filter (36) and into hydraulic tank (1) .When the joystick control is released, the control valve returns to HOLD position. Oil flow to the cylinder is blocked and the ejector will not move.When the