TM 10-3930-669-20 6.  SIDE SHIFT CYLINDER DOES NOT OPERATE (CONT). KNOWN INFO TEST OPTIONS Side shift cylinder hoses OK. Pressure test. STE/ICE-R #51. POSSIBLE PROBLEMS REASON FOR QUESTION Priority valve faulty. Stack valve faulty. Side shift assembly faulty. Side shift cylinder faulty. If   priority   valve   is   faulty,   side shift cylinder will not operate. KNOWN INFO TEST OPTIONS Side shift cylinder hoses OK. Priority valve OK. Pressure test. STE/ICE-R #51. POSSIBLE PROBLEMS REASON FOR QUESTION Stack valve faulty. Side shift assembly faulty. Side shift cylinder faulty. If  stack  valve  is  faulty,  side  shift cylinder will not operate. ¬ ¬ 2-458