MOTOR 0777184 - Caterpillar

Location
Illustration 1 g00567074
(1) Location for the load control valve (if equipped) for the stick (2) Location for the load control valve (if equipped) for the boomThe load control valve for the stick is used in order to hold the stick in place in case of a hose failure in the stick circuit. The load control valve for the boom is used in order to hold the boom in place in case of a hose failure in the boom circuit.Stick
Illustration 2 g00839332
Schematic for the load control valve for the stick (1) Line to the head end of the cylinder, (2) Line to the rod end of the cylinder, (3) Line relief valve, (4) Purging screw, (5) Check valve, (6) Line to the load control valve for the boom, (7) Relief valve, (8) Line to the control valve, (9) Line to the control valve, (10) Check valve, (11) Orifice, (12) Relief valve and (13) Ball check valveIn the HOLD position, check valve (5), check valve (6), and relief valve (7) block the oil in the rod end of the cylinder. This will prevent the stick from falling if a hose failure occurs in the stick circuit.The operator moves the control for the stick in order to move the stick to the STICK OUT position. The oil from the control valve flows through line (8). The oil flows past the check valves (5) and (6). The oil flows through the line to the rod end of cylinder (2). The oil that is pushed out of the head end of the cylinder flows through line (1). The oil flows through orifice (11). The oil opens check valve (10) and flows into the line to the control valve (9). This causes the rod to retract. As the rod retracts, the stick will move outward.The operator moves the control for the stick in order to move the stick to the STICK IN position. The oil from the control valves flows into line (9). Supply oil pressure acts as a signal in order to open valves (7) and (12). The oil flows through orifice (11) and relief valve (12) then into the line for the head end of cylinder (1). This causes the rod of the cylinder to extend. The open relief valve (7) allows the rod end oil to flow back to the control valve as the rod extends. As the rod extends, the stick will move inward. Line relief valve (3) will open in order to protect the cylinder from high pressures while the stick is in the HOLD position.Use purging screw (4) in order to lower the boom, if a hose failure occurs or if loss of hydraulic power occurs. Ball check valve (13) allows the oil to flow into the head end of the stick cylinder when the purging screw is used to lower the stick. The flow of oil into the head end of the cylinder prevents the cylinder from cavitating.Refer to the Operation and Maintenance Manual for the proper procedure to