TM 10-3930-671-24 1. Check    the    engine    oil    level    every    8    hours according  to  engine  oil  dipstick  and  procedures specified below. 2. Pull  the  dipstick  out,  wipe  it  with  a  clean  wiper, and    reinsert    it    fully    into    the    dipstick    tube. Remove the dipstick and check the oil level. 3. Check the PM time interval (operating hours), or the condition of the oil, to determine if it needs to be changed. Oil and Filter Change Procedures It is recommended to: • Drain and replace the engine crankcase oil every   50   to   250*   operating   hours.   See NOTE 4.1-1. • Replace    engine    oil    filter    at    every    oil change. • Drain  and  replace  engine  oil  in  a  new  or rebuilt  engine  after  the  first  50  hours  of operation. • Drain   old   oil   after   truck   has   been   in operation    and    engine    (oil)    is    hot    (at operating temperature). • Do not exceed 250 hours. Refer  to  Section  2.1,  Service  Specifications,  for  engine oil specifications for your engine model. NOTE Raise  and  block-up  the  truck  under  the  frame  to  give easier access to the engine drain plug. Refer to Section 3.3, Machine Jacking and Blocking. 1. To  drain  the  engine  oil,  put  a  low  flat  drain  pan under the truck. Remove drain plug at bottom of oil pan and drain the oil completely. 2. Remove the engine oil filter. If necessary, use a standard filter wrench. 3. Install new oil filter. Follow installation instructions printed on the outside surface of the filter.  Check  that  the  oil  seal  is  lubricated  and correctly in place. 4. Clean  and  inspect  the  oil  drain  plug  and  seal. Replace the drain plug and/or seal if damaged. 5. Install drain plug. Remove oil drain pan. 6. Remove and inspect the condition of the engine oil  filler  cap  located  on  top  of  the  engine  valve cover.  Replace cap if it is damaged or the seal is broken. 7. Refill the crankcase with fresh engine oil through the rocker cover oil filler opening. 8. Wait  several  minutes  after  adding  oil  and  then check the oil level. 9. Start  the  engine  and  allow  it  to  run  at  idle  for several  minutes.  Check  the  oil  filter  and  drain plug for leakage. 10. Check    the    engine    oil    level    with    the    engine stopped.    Refer  to  procedures  noted  above  for your engine model. F-66