TM 10-3930-669-20 2-18.  HYDRAULIC SYSTEM TROUBLESHOOTING (CONT). 7.  LIFT CYLINDER(S) DOES NOT OPERATE. INITIAL SETUP Tools and Special Tools Tool Kit, General Mechanic's: Automotive (Item 1, Appendix B) Pressure Test Kit (Item 2, Appendix B) STE/ICE-R (Optional) (Item 14, Appendix B) Personnel Required Two Materials/Parts Cap and plug Set (Item 5, Appendix C) Tags, Identification (Item 21, Appendix C) References TM 10-3930-669-10 Equipment Condition Engine OFF (TM 10-3930-669-10) MAIN POWER switch OFF (TM 10-3930-669-10) Parking brake applied (TM 10-3930-669-10) Wheels chocked (TM 10-3930-669-10) KNOWN INFO TEST OPTIONS Side shift cylinder operates. Visual inspection. POSSIBLE PROBLEMS REASON FOR QUESTION Lift cylinder hose(s) leaking or damaged. Stack valve faulty. Secondary flow regulator faulty. Mast assembly faulty. Lift cylinder faulty. If  lift  cylinder  hose(s)  is  loose  or damaged,  tilt  and  pivot  cylinders will   not   operate   or   will   operate slowly. ¬ 2-462