TM 10-3930-669-20 8.  LOAD CANNOT BE LIFTED TO MAXIMUM HEIGHT (CONT). KNOWN INFO TEST OPTIONS Transmission operates. Hydraulic fluid level OK. Hydraulic  tank  to  pump  suction  hose OK. Hydraulic pump OK. Priority valve OK. Pressure test. STE/ICE-R #51. POSSIBLE PROBLEMS REASON FOR QUESTION Stack valve faulty. Mast adjustment faulty. It     stack     valve     is     faulty,     lift cylinders    will    not    lift    load    to maximum  height.    If  stack  valve is OK, mast adjustment is faulty. KNOWN INFO TEST OPTIONS Transmission operates. Hydraulic fluid level OK. Hydraulic  tank  to  pump  suction  hose OK. Hydraulic pump OK. Priority valve OK. Stack valve OK. Mast adjustment OK. Verify repair. POSSIBLE PROBLEMS REASON FOR QUESTION If lift cylinders lift load to maximum  height,  fault  has  been corrected. ¬ ¬ 2-472