TM 5-3825-226-24 The    setting    of    the    relief    valve    for    maximum pressure must be according to the Service Manual. CAUTION:  When  the  pressures  are  higher  than  1000 psi,  slowly  open  the  manual  load  valve  before  turning the  steering  wheel  back  to  center.    This  will  prevent possible damage to the pressure gauge. Test 2: System Oil Temperature 1. Open the manual load valve fully. 2. Turn  the  steering  wheel  to  the  RIGHT  TURN position. 3. Write down the oil temperature. Test 3: System Base Flow Rate 1. Open the manual load valve fully. 2. Turn  the  steering  wheel  to  the  RIGHT  TURN position. 3. Run the engine at test rpm. 4. Check pressure to make sure it is at a minimum valve of approximately 100 psi. 5. Write down the flow rate (gpm). The base flow rate of the system will be the same as the  low  pressure  flow  of  the  hydraulic  pump.    Because there  will  be  minimum  leakage  in  the  control  valves, lines and cylinder packings at 100 psi, the base flow rate can be used to find the flow differential in Tests 4 and 5. NOTE: If the base flow rate (Test 3) is less than the flow rate in Test 4, do Test 4 first and then Test 3.  For vane pumps  only,  this  takes  place  when  the  vanes  in  the pump do not have full extension at low pressure. Tests 4 and 5: Leakage Rates These  two  tests  are  similar.    Each  test  is  done  as follows: 1. Move    the    steering    wheel    to    the    respective TURN positions. 2. Run the engine at test rpm. 3. Make an adjustment to the manual load valve to get 1000 psi pressure. 4. Make the system constant with these conditions. 5. Write down the flow rate (gpm) for each test. The flow differential for each test (4 and 5) is found by taking  the  flow  rate  for  each  test  away  from  the  base flow rate (Test 3).  The percent of flow loss for each test (4  and  5)  is  found  by  dividing  the  flow  differential  for each test by the base flow rate (Test 3). Test 10: System Oil Temperature 1. Open the manual load valve fully. 2. Turn  the  steering  wheel  to  the  RIGHT  TURN position. 3. Write down the oil temperature. Make   a   comparison   of   the   oil   temperature   from Tests 2 and 10.  Test 2 must be 150 ±  5°  F and Test 10 must be inside of (within) 10°  F of Test 2.  For each 10° F  higher  difference  (Test  10  higher  than  Test  2),  take away  .5  gallon  per  pump  cartridge  from  the  leakage rate.  For each 10°  F lower difference, add .5 gallon per pump cartridge to the leakage rate. Is It Necessary To Make More Tests? If so, Which Circuit(s)? Make a comparison of the test data with the data on Chart   A   for   the   specific   machine   under   test.      The percent  of  flow  loss  on  Chart  A  is  maximum  for  best performance. Components that are worn, or not working correctly, are  found  by  their  flow  differential  and  percent  of  flow loss or lower system efficiency.  System values for new and rebuilt machines must not be more than the percent of flow loss in the system tests shown on Chart A for the specific machine.  The permissible flow differential is a function  of  machine  application.    For  applications  with low  travel  speeds,  the  permissible  flow  differential  can be more than for applications with high travel speeds. If  the  percent  of  flow  loss  is  acceptable,  the  Tee Test is completed. If the percent of flow loss is not acceptable, the tests for the pump and/or the blocked cylinders must be done. Troubleshooting The  following  examples  are  a  list  of  problems  and probable reasons.  They will aid in finding the 2-117