ARMY TM 9-2815-257-24 AIR FORCE TO 38G1-128-2 MARINE CORPS TM 10155A/2815-24/3 3-8 Table 3-1.  Unit Level Preventive Maintenance Checks and Services for Engine Assembly Item No. Interval Location: Item to Check/ Service Procedure Not Fully Mission Capable If: 1 100 hours Lubricating oil system NOTE: First oil service occurs after 25 hours of operation.  100 hour intervals thereafter. Service engine lubricating oil (Para. 3-6).   Engine oil has not been changed. 2 100 hours Oil filter Remove and clean engine oil filter (Para. 3-18).  Replace as required. Oil filter is clogged, dirty, or damaged. 3 500 hours Air filter Remove and replace air filter (Para. 3-16).   Air filter is dirty or damaged. 4 500 hours Fuel injection pump a.  Inspect fuel injection pump for damage      and evidence of leakage. b.  Check area around pump sealing gasket      for leaks.  Remove and replace gasket      as required (refer to Direct Support      Maintenance). Fuel leak of any kind is present. 5 500 hours Valve clearance Adjust valve clearance (Para. 3-15). Valves are not properly adjusted, causing improper engine operation. 6 1000 hours Fuel injector nozzle Remove and replace fuel injector nozzle (Para. 3-14). Fuel injector nozzle has not been replaced.