The pilot manifold is used to direct the flow of hydraulic fluid and pressure to different areas of the hydraulic system. Those areas include the steering system, implement valve, hydraulic tank, and accumulator. The pilot manifold houses the implement lockout valve.
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| Illustration 1 | g06183471 |
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Pilot Manifold (1) Implement lockout valve (2) Pilot manifold (3) Accumulator (4) Pilot /Steering charge filter group (5) From steering charge system (6) Hydraulic pilot supply (7) Tank or pilot drain (EE) Pneumatic pressure (FF) Activated component (GG) Tank pressure (RR) Charge or pilot pressure (SS) First pilot pressure reduction | |
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| Illustration 2 | g06308990 |
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(1) Implement lockout valve
(8) Solenoid (9) Passage to implement control valves (10) Passage to hydraulic oil tank | |
Implement lockout valve (1) is located in the pilot manifold.
When the machine is on and the implement lockout switch is in the OFF (unlocked) position, solenoid (8) is energized. Solenoid (8) is de-energized when the engine speed is below 800 rpm and no implement is commanded to move. When solenoid (8) is energized, the valve directs the pilot oil to passage (6). Pilot supply now flows through the end cover into the implement valve pilot supply rail. The pilot supply rail distributes the pilot supply oil to either end of each implement control valve.
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| Illustration 3 | g01032610 |
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Accumulator | |
The accumulator is on the top of the pilot manifold.
The accumulator contains a bladder that separates oil and dry nitrogen gas. The accumulator stores potential energy by accumulating a quantity of pressurized hydraulic oil. The oil that is stored is available to the pilot circuit when extra pressure is needed.
The accumulator provides oil to the pilot circuit as makeup oil to stabilize the pilot oil supply. Also, the accumulator provides oil through the implement lockout valve to lower the implements for a short time after the machine is shut down.
The accumulator is filled by pilot oil in the pilot manifold. Also, the pilot manifold contains a check valve to prevent the stored oil from flowing back into the steering charge supply line.