LUBRICATION    SYSTEM it.  Operation  of  the  engine  with  low  oil  pressure can he the cause of engine failure or of a reduc- tion  in  engine  life. ENGINE OIL PRESSURE CHART MINIMUM   PERMISSIBLE PRESSURE TEST r p m SAE  NO. OF TEST OIL p  s  i k P a 1500   rpm or  above 1 0 2 0 1 4 0 3 0 2 4 1 6 5 1 0 6 4 0 3 0 7 5 0 600  to  800 rpm Crankcase   Oil   Level Check  the  level  of  the  oil  in  the  crankcase.  Add  oil if needed. It is possible for the oil level to be too far below  the  oil  pump  supply,  tube.  This  will  cause  the oil pump to not have the ability to supply enough lubrication  to  the  engine  components. Oil  Pump  Does  Not  Work  Correctly The inlet screen of the supply tube for the oil pump can  have  a  restriction.  This  will  cause  cavitation  (the sudden  making  of  low  pressure  bubbles  in  liquids  by mechanical forces) and a loss of oil pressure. Air leakage  in  the  supply  side  of  the  oil  pump  will  also cause cavitation and loss of oil pressure. If the bypass valve  for  the  oil  pump  is  held  in  the  open  (unseated) position,  the  lubrication  system  can  not  get  to  maxi- mum  pressure.  Oil  pump  gears  that  have  too  much wear  will  cause  a  reduction  in  oil  pressure. Oil Filter and Oil Cooler Bypass Valves If  the  bypass  valve  for  the  oil  filter  or  oil  cooler  is held  in  the  open  position  (unseated)  and  the  oil  filter TESTING   AND   ADJUSTING TM  5-3805-263-14&P-2 or oil cooler has a restriction, a reduction in oil pressure  can  be  the  result.  To  correct  this  problem, install  a  new  oil  filter. Too Much Clearance at Engine Bearings or Open Lubrication System (Broken or Disconnected  Oil  Line  or  Passage) Components that are worn and have too much bearing  clearance  can  cause  oil  pressure  to  be  low. Low  oil  pressure  can  also  be  caused  by  an  oil  line  or oil  passage  that  is  open,  broken  or  disconnected. Oil Cooler Look  for  a  restriction  in  the  oil  passages  of  the  oil cooler. If the oil cooler has a restriction, the oil temperature will be higher than normal when the engine  is  running.  The  oil  pressure  of  the  engine  will not  get  low  just  because  the  oil  cooler  has  a restriction. OIL   PRESSURE   IS   HIGH Oil pressure will be high if the bypass valve for the oil  pump  can  not  move  from  the  closed  position. TOO  MUCH  BEARING  WEAR When  some  components  of  the  engine  show  bear- ing wear in a short time, the cause can be a restriction in an oil passage. A broken oil passage can also be the cause. If the gauge for oil pressure shows enough good oil pressure,  but  a  component  is  worn  because  it  is  not getting  enough  lubrication,  look  at  the  passage  for  oil supply  to  that  component.  A  restriction  in  a  supply passage  will  not  let  enough  lubrication  get  to  a  com- ponent  and  this  will  cause  early  wear. 1-63