TM 5-3825-226-24 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 1500  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. 2-120