TM 5-3805-258-24-1H Y D R A U L I C S Y S T E MS Y S T E M S O P E R A T I O NLIFT AND TILT PILOT VALVE(Lift and Lower Stems in HOLD Position)1. Actuator. 2. Lift control shaft. 3. Plunger (lower). 4.Plunger (lift). 5. Retainer. 6. Retainer. 7. Meteringspring.8. Metaring spring.9. Centering spring. 10. Cen-tering spring.11. Tank passage. 12. Lower stem. 13. Liftstare.14. Holes. 15. Holaa. 16. Vent passage. 17. Tankpaaaaga. 18. Passage to lift valvespool. 19. Passage to liftvalva spool. 20. Pump (supply) passage. 21. Passage totilt valve spool (dump stem). 22. Passage to tilt valvespool(tilt back stem).Spring (10) pushes up on retainer (5) and plunger(3). Spring (8) holds lower stem (12) down againstretainer (5). Spring (9) pushes upon retainer (6) andplunger (4). Spring (7) holds lift stem (13) downagainst retainer (6). There are spacers between theretainers and plungers that are used to change theforce of springs (7) and (8).LIFT ANDTILT PILOT VALVE(Lift Stem in RAISE Position)1. Actuator. 2. Lift control shaft. 4. Plunger (lift). 6. Re-tainer. 7. Metering spring. 6. Metering spring. 9. Center-ing spring. 11. Tank passage. 12. Lowerstem. 13. Liftstem. 14. Holes. 15. Holes. 18. Passage to lift valvespool. 19. Passaga to lift valvespool. 20. Pump (supply)passage.When the lift control lever is moved into RAISEposition, the control lever turns shaft (2) and actua-tor (1) in the direction shown. The actuator pushesplunger (4) down against the force of spring (9). Liftstem (13) moves down with the plunger. The oil frompump passage (20) now goes through holes (15) andout passage (19) to one end of the lift valve spool. Thepressure of this oil on the end of the lift valve spoolmoves the spool into RAISE position.The oil from the chamber at the opposite end of thelift valve spool comes back through passage (18).This oil goes through holes (14) of lower stem (12)into tank passage (11).Oil pressure in passage (19) pushes up against liftstem (13) and spring (7). A small pressure increasein passage (19) pushes lift stem (13) up against theforce of spring (7). The flow of pressure oil throughholes (15) and passage (19) is stopped [the pressure3-96
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business