TM 5-3805-260-24 Test 40: Flow    rate    of    pump    and    unloading valve. Test 17: Flow  rate  of  pump,  control  valve  and unloading valve. The  components  tested  in  Tests  40  and  17  are the same except for the control valve.  The difference in the flow rates must be caused by leakage in the control valve. Make  a  comparison  of  all  the  test  data  with  the data   on   Chart   D   for   the   machine   under   test.      The information on Chart D is for best circuit performance. Troubleshooting PROBLEM:  Leakage  rates  for  Tests  34,  35,  36,  37, and 38 are more than the rates shown in Chart D. PROBABLE REASON: Leakage in the pressure relief valve. RECOMMENDATION FOR ACTION: Inspect pressure relief valve. PROBLEM:    Tests    34    and    35    give    an    indication    of leakage in the ejector circuit. PROBABLE REASON: A.  Leakage in the ejector cylinders. B.  Leakage in the floor cylinder. C.      Leakage   in   the   floor   check   valve   (ejector check valve). RECOMMENDATION FOR ACTION: Do Tests 43 and 44 for the ejector circuit. PROBLEM:  Tests  36  and   37   give   an   indication   of leakage in the bowl circuit. PROBABLE REASON: A.    Leakage  in  only  one  of  the  cylinders  and check valve. B.  Leakage in both cylinders and check valve. RECOMMENDATION FOR ACTION: Do Tests 45 and 46 for the bowl circuit. PROBLEM:  Motor leakage rate in Tests 38, 39 and 40 is more than shown in Chart D. PROBABLE REASON: Leakage in the motor. RECOMMENDATION FOR ACTION: Disassemble   and   inspect   the   elevator   motor. Make a repair or install new parts as necessary. PROBLEM:  Leakage   rate   in   Test   40   is   more   than shown in Chart D. PROBABLE REASON: Damage in the control valve. RECOMMENDATION FOR ACTION: Disassemble    and    inspect    the    control    valve. Make a repair or install new parts as necessary. PROBLEM:  Leakage rate for Tests 34, 35, 36 and 37 are more than shown in Chart D. PROBABLE REASON: Leakage in the pressure relief valve. RECOMMENDATION FOR ACTION: Inspect pressure relief valve. BLOCKED COMPONENT TESTS (CHART E) If the Blocked Circuit Tests give an indication of leakage that is too high in cylinders, valves, or motor, do the   Blocked   Component   Tests.      For   best   accuracy, operate   all   controls   through   several   cycles   to   get   the temperature   of   oil   in   the   cylinders   the   same   as   the temperature  of  the  oil  in  the  hydraulic  tank.    Make  the temperature of the oil in the complete system 150° F. WARNING:      Lower   all   implements   to   the ground.    Stop  the  engine.    Move  the  control levers   through   OPERATE   and   HOLD   posi- tions    to    release    any    pressure    oil    in    the hydraulic   lines.      All   pressure   in   the   lines   must   be released  to  prevent  injury  to  personnel  and  damage  to equipment when the lines are loosened.  To loosen the lines with pressure oil in them can cause the implement to  move  and/or  pressure  oil  to  be  released.    Open  the filler   cap   for   the   hydraulic   tank   to   release   any   tank pressure.  Close the cap. Tee locations are not the same for all tests.  At the  beginning  of  each  test,  tee  locations  and  blocking locations   are   explained.      See   the   schematics   and illustrations for the specific machine being tested. 4-52