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| Illustration 1 | g01285196 |
Schematic of the pilot hydraulic system (with the optional auxiliary pilot hydraulic system) (1) Lift arm positioner valve (2) Line to lift spool of main control valve (3) Float sequence valve (4) Vent line from main control valve (5) Pilot oil return (6) Manifold (7) Line and orifice (8) Pilot oil return (9) Pilot diverter solenoid valve (if equipped) (10) Line to auxiliary spool of the main control valve (if equipped) (11) Line to tilt spool of main control valve (12) Line to auxiliary spool of the main control valve (if equipped) (13) Line to tilt spool of main control valve (14) Pilot control valve (15) Line to lift spool of main control valve (16) Pilot diverter solenoid valve (if equipped) (17) Lower valve stem (18) Raise valve stem (19) Dump valve stem (20) Tilt back valve stem (21) Pilot oil supply | |
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| Illustration 2 | g01285199 |
(22) Switch (to operate the pilot diverter solenoid valves) (23) Joystick control lever | |
Pilot control valve (14) uses only one control lever (joystick type) to control the operations of both the lift function and the tilt function. Joystick control lever (23) is operated manually by the operator. The joystick control lever is connected to a pivot plate that contacts the four rods for RAISE, LOWER, DUMP and TILT BACK positions. The pilot control valve sends pilot pressure oil to operate the lift spool and the tilt spool in the main control valve.
When joystick control lever (23) is moved to a position, pilot oil flows from pilot control valve (14) to the main control valve. This causes the lift spool or the tilt spool in the main control valve to move. Movement of the lift spool opens the passage for implement oil flow to the lift cylinders. Movement of the tilt spool opens the passage for implement oil flow to the tilt cylinder. Oil lines (2), (11), (13) and (15) connect the output of the pilot control valve to the pilot inlets for the lift spool and the tilt spool in the main control valve.
The pilot control valve section for tilt control has three positions; TILT BACK, HOLD and DUMP. The pilot control valve section for lift control has four positions; RAISE, HOLD, LOWER and FLOAT. The pilot control valve is a closed center valve. Pilot oil cannot flow through pilot control valve (14) when it is in the HOLD position.
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| Illustration 3 | g01285200 |
Location of the pilot diverter solenoid valves (9) Pilot diverter solenoid valve (16) Pilot diverter solenoid valve | |
Note: The optional auxiliary pilot hydraulic system controls the ejector bucket.
Pilot diverter solenoid valves (9) and (16) are additional components in the optional auxiliary pilot hydraulic system.
When the auxiliary pilot hydraulic system is activated, the DUMP position changes to the EJECT position. Also the TILT BACK position changes to the RETRACT position.
Switch (22) activates the pilot diverter solenoid valves and allows pilot oil to be diverted to either end of the auxiliary spool in the main control valve. To activate the auxiliary pilot hydraulic system, press and hold switch (22) while joystick control lever (23) is moved to the EJECT or RETRACT positions. Oil lines (10) and (12) connect the output of the pilot control valve to the pilot inlets on the auxiliary spool in the main control valve.