TM 10-3930-669-20 3.  PIVOT CYLINDER DOES NOT OPERATE OR OPERATES SLOWLY (CONT). KNOWN INFO Lift, shift, and tilt cylinders operate. Pivot cylinder pins OK. Hydraulic hoses to pivot cylinder OK. Pivot control cable OK. POSSIBLE PROBLEMS Stack valve faulty. Pivot cylinder faulty. Pivot shaft bearings faulty. TEST OPTIONS Pressure test. STE/ICE-R #51. REASON FOR QUESTION If stack valve is faulty, pivot cylinder will not operate. 2-440