TM 9-6115-668-13 Table 4-3.  Unit Preventive Maintenance Checks and Services for Generator Set 150 kW. Item Item to be Not Fully Mission No. Interval Checked or Serviced Procedure Capable if: 1 125 Engine Preheating Assembly Check operation.  Refer to paragraph Diesel engine cannot Hours 2.8 be preheated. 2 250 V Belts (Battery Charging a.  Check V belt tension and readjust V belts are loose, Hours/ Alternator) if necessary.  Check V belts for dam- frayed, or damaged. Semi age, and replace defective V belts. Annual Refer to paragraphs 4.34 and 4.35. b.  Below 23 F (-5 C), install V belts for winter operation.  Refer to paragraph 4.35. 3 250 Engine Oil Change Engine Oil (Refer to para- Class III oil leak. Hours/ graph 2.3.3.3) for oil change intervals Semi under unusual conditions. Annual 4 250 Oil Filter Replace oil filter at every other oil Class III oil leak. Hours/ change, or at intervals of 250 hours or Semi less.  Refer to paragraph 4.30. Annual 5 250 Subcurrent Filter Assembly Replace filter cartridge at every other Class III oil leak. Hours/ oil change, or when subcurrent filter Semi does not get hot during operation Annual (250 Hours or less).  Refer to para- graph 4.31. 6 250 Fuel Prefilter and Two Step a.  Clean or replace filter cartridges. Diesel engine runs Hours/ Fuel Filter Assembly Refer to paragraph 4.32 and 4.33. roughly with poor Semi output or any fuel Annual leak. b.  Bleed fuel filter after filter insets Any fuel leak. are cleaned or replaced.  Refer to paragraphs 4.38 and 4.39. 7 1000 Synchronous Generator Lubricate bearings.  Refer to para- Hours/ Assembly graph 4.7.  Perform load bank proce- Annual dures in accordance with paragraph 5.53. 4-18  Change 2