SERVICE AR 4783435 - Caterpillar

Illustration 1 g00987703
Ejector Circuit (Ejector Return) (1) Oil line for ejector cylinder (2) Oil line for apron cylinder (3) Main control valve (4) Oil line for return oil (5) Oil line to hydraulic tank (6) Ejector valve stem (7) Sequence and pressure control valve (apron) (8) Common oil line to apron cylinder (9) Oil line for bowl cylinders (10) Apron cylinder (11) Common oil line for ejector cylinder (12) Apron valve stem (13) Vent lines for quick-drop and check valves (14) Bowl valve stem (15) Oil line for head end of ejector cylinder (16) Oil filter (17) Relief valve (18) Oil line for bowl cylinders (19) Oil line to rod end of ejector cylinder (20) Hydraulic tank (21) Oil line to main control valve (22) Speed change valve for the ejector (23) Ejector cylinder (24) Oil pump for implement system (A) RETURN (Override) position (B) RETURN position (C) HOLD position (D) EJECT position (AA) Pump pressure oil (BB) Tank oil (CC) Blocked oilEjector Control in RETURN PositionEjector valve stem (6) uses two positions to return the ejector. Detent balls keep ejector valve stem (6) in RETURN position (B). The ejector control lever must be held in RETURN (override) position (A) or the spring on the end of ejector valve stem (6) moves the valve stem back to RETURN position (B).
Illustration 2 g00987832
Ejector Valve Stem in RETURN (Override) Position (25) Detent ball (26) Retainer (27) Retainer (28) Passage in ejector valve stem (29) Valve (30) Spring (31) SpringThe oil from pump (24) flows through line (21) to main control valve (3). The oil then flows to ejector valve stem (6). The pump oil flows around ejector valve stem (6) through common oil line (11) and through speed change valve (22). The pump oil flows through oil line (19) into the rod end of ejector cylinder (23). The pump oil in the rod end moves the piston and the rod that is connected to the ejector. When ejector valve stem (6) is moved to RETURN position and the piston is fully extended, pump oil flows into the rod end of ejector cylinder (23). The pump oil also flows into common oil line (11), passage (28), and oil line (19) .Pressure oil in passage (28) opens valve (29) and flows into a chamber between retainers (26) and (27). The pressure oil in the chamber moves retainer (26). The retainer moves ejector valve stem (6). When ejector valve stem (6) moves over detent balls (25), springs (30) and (31) move retainers (26) and (27). Retainer (26) then moves ejector valve stem (6) to HOLD position (C) .Ejector Control in EJECT PositionWhen the ejector valve stem is in EJECT position (D), the pump oil in main control valve (3) flows around ejector valve stem (6). The pump oil then flows through oil line (1) to speed change valve (22). The pump oil will flow through speed change valve (22) and oil line (15) into