CONTROL VALVE GROUP 9J2919 - Caterpillar

LOWER Operation
When the lift control lever is moved to the LOWER position, pilot oil is sent to the left end of lift valve stem (21). Lift valve stem (21) moves partially to the right. Implement oil is sent from pump port (54) around lift valve stem (21) to the right side of compensation and load check valve (56) and (57). Compensation and load check valve (56) is pushed to the left and flow goes through the openings in the compensator (56) to bridge passage (51).Oil is allowed to flow to the rod end of the lift cylinders. The bucket will lower. Solenoid valves (9B) and lift valve stem (21) respond in proportion to the movement of the operator controls.Oil from the head end of the lift cylinders enters through work port (44). The oil flows through check valve (23) and poppet valve for drift reduction and exits at tank port (33) to the hydraulic tank.FLOAT Operation
When the lift control lever is moved to the FLOAT position, pilot oil is sent to the left end of lift valve stem (21). Lift valve stem (21) moves completely to the right. The lift control lever is held in the FLOAT position by a soft detent. The lift valve stem remains in the float position until the bucket reaches the preset kickout position. The lift control valve will then return to the HOLD position.When the stem moves to the FLOAT position, work port (44) is connected to the tank at port (33) through shifted lift valve stem (21). Complete movement of lift valve stem (21) to the right closes off the flow of pump oil from port (54) to bridge passage (51). Work port (41) continues to be connected to the tank and lift valve stem (21).Oil from the rod end of the lift cylinder and the oil from the head end of the lift cylinder drains to the tank. The weight of the lift arm assembly lowers the lift arm assembly to the ground. The lift arm assembly will follow the contour of the ground. Neither the rod end of the lift cylinder or the head end of the lift cylinder are under hydraulic pressure. The lift cylinders can move freely in either direction according to the force on the bucket.Reference: For more information on the operation or the solenoid valves, refer to Systems Operation, "Solenoid Valve (Implement)".Ride Control Valve
Illustration 11 g03080283
Ride control valve
(7) Ride control PED relief
(8) Ride control pressure limiter
(60) Dynamic seal
(61) Retention plug
(62) Sleeve
(63) Activation spool
(64) Balance spool
(65) Charging spool
(66) Charging ManifoldRide control valve is an optional control addition to the main implement valve. This function provides dampening for the forces that are produced by the bucket as the machine travels over rough terrain. Ride control valve has three states: AUTO, OFF and SERVICE. Details about the three states of the ride control valve can be found in Systems Operation, "Ride Control System".When ride control is not activated, the balance solenoid (11) disconnects the accumulator from the balance spool