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| Illustration 1 | g01053617 |
Pilot Hydraulic System (1) Pilot control actuators. (2) Pressure reducing valve. (3) Solenoid valve (hydraulic lockout). (4) Check valve. (5) Pilot relief valve. (6) Pilot pump. (7) Hydraulic tank. | |
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| Illustration 2 | g01053777 |
Right Side of Platform (7) Hydraulic tank. (8) Filler cap. (9) Breaker relief valve. | |
Hydraulic tank (7) is beneath the access door on the right cab platform. Add oil by removing filler cap (8). Breaker relief valve (9) is used for relieving excessive pressure or vacuum from hydraulic tank (7). Hydraulic tank (7) also has three screens for return oil, an ecology drain valve for draining the oil, and a sight gauge for checking the oil level.
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| Illustration 3 | g01053699 |
Pump Compartment (6) Pilot pump. (10) Variable displacement piston pump. (11) Fixed displacement piston pump. (12) Hydraulic filter. | |
The pump compartment is beneath the access doors in the platform behind the cab. Pilot pump (6) is a gear pump that is mounted on the front of variable displacement piston pump (10). The pilot pump provides pilot oil to the implement system.
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| Illustration 4 | g00658081 |
Pump Compartment (12) Implement oil filter. (13) Filter bypass switch. | |
The oil that is provided by the pilot pump flows through implement oil filter (12). Implement oil filter (12) is equipped with a bypass valve in the filter mounting base. When the filter is plugged, the filter bypass valve opens and oil flows over the check valve. Then, switch (13) opens and the VIDS/VIMS ELECTRONIC CONTROL or the VIMS main module will activate an alert indicator in the cab so that the operator is aware of the problem.
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| Illustration 5 | g01053709 |
Inside of Right Front Frame (5) Pilot relief valve. | |
Pilot relief valve (5) is fastened to the inside of the right front frame below the filter. Pilot oil from the filter flows to the pilot relief valve. The pilot relief valve maintains the pressure in the pilot hydraulic system at 2400 kPa (350 psi) at 35 L/min (9.3 US gpm).
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| Illustration 6 | g01053778 |
Main Control Valve (Left) (1) Pilot Control Actuator. | |
Pilot control actuators (1) control the flow of pilot oil from the spools in the main control valve back to the hydraulic tank. As current from the implement electronic control module (ECM) is applied to one pilot control actuator, the actuator will begin to shift. Trapped oil from behind the stem in the main control valve will begin to drain pilot oil from the actuator. The spring force on the opposite side of the stem will shift the stem. The movement of the stem is proportional to the current that is applied to the pilot control actuator. Oil that is supplied from the implement pumps to the main control valves will flow to the respective cylinder. As the current to the actuator is removed, the actuator shifts back to the relaxed position. Then, the oil is trapped between the stem and the actuator. The combination of the oil pressure and the spring force to each end of the stem is equalized.