TM 10-3930-669-20 WARNING •  High-pressure hydraulics [oil under 3,000 psi (20,700 kPa) pressure] operate this equipment.  Refer to vehicle operator  and  maintenance  manuals  for  hydraulic  oil  pressure.    Never  disconnect  any  hydraulic  line  or  fitting without first dropping pressure to zero.  Failure to comply may result in injury to personnel. • Hydraulic oil is slippery and can cause falls.  To avoid injury, wipe up spilled oil with rags. PRESSURE TEST (1) Tag and disconnect pivot out hose from pivot cylinder. (2) Connect a 0 to 4,000 psi (0-27,567 kPa) pressure gauge to pivot out hose. (3) Install pressure cap on pivot cylinder open port. (4) Start engine (TM 10-3930-669-10). (5) With aid of an assistant, move  pivot/shift joystick in pivot out position and observe pressure gauge (TM 10-3930-669-10). (a) if 2,000 to 2,600 psi (13,780- 17,920 kPa) are not measured, stack valve is faulty.   Perform Steps (6) and (7) below and notify DS Maintenance. (b) If 2,000 to 2,600 psi (13,780- 17,920 kPa) are measured, stack valve is OK. (6) Shut down engine. (7) Remove pressure gauge, tag, and cap and connect pivot out hose to pivot cylinder. 2-441