Illustration 1 | g06127525 |
Pilot hydraulic system (1) Tilt cylinder (2) Regeneration valve (3) Lift cylinders (4) Switch (hydraulic lockout) (5) Shuttle valve (6) Pressure reducing valve (7) Tilt linkage position sensor (8) Lift linkage position sensor (9) Main control valve (left) (10) Float valve (left) (11) Float valve (right) (12) Main control valve (right) (13) Cat Data Link (14) Implement electronic control module (ECM) (15) Hydraulic lockout valve (16) Tilt lever position sensor (17) Lift lever position sensor (18) Implement pilot relief valve (19) Implement pump (20) Pilot pump (Steering) (STIC) (21) Implement pump (22) Hydraulic tank |
Illustration 2 | g06234440 |
(22) Hydraulic tank
(23) Breaker relief valve (24) Filler cap (25) Sight gauge |
Hydraulic oil tank (22) is beneath the access door on the right cab platform. Add oil by removing filler cap (24). Breaker relief valve (23) is used for relieving excessive pressure or vacuum from the hydraulic tank. The hydraulic oil tank also has three screens for return oil. The tank also has an ecology drain valve for draining the oil, and a sight gauge (25) for checking the oil level.
Illustration 3 | g06234528 |
Pump compartment (19) Implement pump (center) (21) Implement pump (right) |
Illustration 4 | g06234531 |
(20) Fan pump (Implement Pilot) |
The implement pump compartment is beneath the access doors in the platform behind the cab. Fan/pilot pump (20) is mounted on the other side of the pump housing on the same side as implement pump (21). Fan pump (20) provides oil to the hydraulic fan system, which is pressure reduced for the implement pilot system.
Illustration 5 | g06128502 |
(26) Implement pilot oil filter
(27) Bypass switch for implement pilot oil |
The oil that is provided by the implement pilot pump flows through implement pilot oil filter (26). Implement pilot oil filter (26) 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 (27) opens and the VIMS main module will activate an alert indicator in the cab. This action makes the operator aware of the problem.
Illustration 6 | g06127983 |
(18) Implement pilot relief valve |
Implement pilot relief valve (18) is fastened to the inside of the left rear 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
Illustration 7 | g06234442 |
(28) Pilot control actuators |
Pilot control actuators (28) 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 force on the opposite side of the stem, generated by the pilot supply pressure 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.