TM 5-3805-260-24 CAUTION: Immediately after stopping the diesel engine, remove the Blocking Plate Assembly from the return line on   the   control   valve.      This   will   prevent   any   possible damage later. Troubleshooting PROBLEM:  The  percent  of  flow  loss  for  Test  15  is 10% or MORE.  Flow differential for Test 15 is 2 gpm or MORE than flow differential for Test 17.  Tests 18 through 25 have the same flow differential. PROBABLE REASON: Oil aeration (low oil level,  hydraulic oil that is not the correct type,  air leak in the suction line for the pump,  oil leaks   in   the   tank   such   as   failure   of    seals,        loose connections or pump cartridge is not installed correctly in pump body). RECOMMENDATION FOR ACTION: A.    Check  oil  level  and  type  of  hydraulic  oil  being used. B.    Check  suction  line  for  air  leaks  [Put  foam  (like shaving  cream)  on  all  connections.    The  foam will    be    pulled    into    the    line    at    any    point    of leakage.] C.    Remove  cover  from  hydraulic  tank  and  inspect for oil leak (check above the oil level first). D.        Disassemble    pump    and    check    for    correct assembly. PROBLEM:   Flow   differential   between   each   of   the Tests 18 through 25 suddenly becomes lower  at  one  test  and  the  flow  rate  is the same for the remainder of the tests at higher engine speed (rpm). Example:   8   gpm   differential   between Tests 18 and 19.  19 and 20,  20 and 21, but  1  gpm  differential  between  21  and 22 and flow rates  for  Tests  23,    24  and 25 are the same as 22. PROBABLE REASON: Pump  cavitation  (restriction  in  the  suction  line   for   the pump). RECOMMENDATION FOR ACTION: Inspect suction line and tank. BLOCKED    CYLINDER    TESTS    (CHART    C)    If    the System   Tests   and   Pump   Test   give   an   indication   of leakage in the control valves and/or cylinders that is not acceptable,  do the Blocked Cylinder Tests. Blocking  Plate  Assemblies  or  Caps  and  Plugs  can be  put  in  each  of  the  cylinder  lines.    For  best  accuracy, do   these   tests   with   the   oil   temperature   approximately 150°  F  (near  the  oil  temperature  for  the  System  Tests and Pump Test). WARNING:   Install   the   safety   link.      Lower   all implements to the ground.  Move the steering wheel from RIGHT  TURN  to  LEFT  TURN  several  times  to  release any pressure oil in the cylinder lines.  All pressure in the lines   must   be   released   or   injury   to   personnel   and damage  to  equipment  can  result  while  loosening  the lines to install or remove the plate assemblies. All Cylinders Blocked 1.  Put control levers in HOLD position. 2.  Open the manual load valve fully. 3.  Start the diesel engine. Test 26: System Oil Temperature 1.    Turn  the  steering  wheel  to  the  RIGHT  TURN position. 2.    Run  the  engine  at  any  rpm  with  the  system pressure at 0 to 100 psi, 3.  Write down the oil temperature. Test 27 and 28: Leakage Rates These two tests are similar.  Do the tests as follows: 1.  With the manual load valve fully open,   turn  the steering wheel to the RIGHT TURN position. 2.  Run the engine at test rpm. 3.    Slowly  close  the  manual  load  valve  to  get  1000 psi pressure. 4.  Write down the flow rate (gpm). 5.    Do  this  procedure   again   in   the   LEFT   TURN position. Test 33: System Oil Temperature 1.  Turn the steering wheel to the RIGHT TURN position. 2-122