TM 9-6115-648-14&P Item no. 4 5 6 7 8 9 10 11 12 13 14 15 Table 4-1. Unit Preventive Maintenance Checks and Services (PMCS) (cont). H - Hours of operation M – Monthly S - Semiannually (As  indicated) H 300 300 300 AR Interval M l l l s (100 hours) (500  hours) Item to be inspected Fuel  Pumps Batteries V-Belts Fuel Filters Fuel  Strainer Lubricating  Oil  and  Filter Breather  and Breather  Tube Air Cleaner Taillights Intervehicular Cable Lunette Safety  Chains Procedures Clean  or  replace,  as  necessary,  fuel  strainer  in bottom of fuel pump. Perform  a  hydrometer  test  on  batteries  every 100 hours. Refer to TM 5-6115-545-12 for test  procedures. Inspect  for  worn,  frayed,  oil  soaked,  or  cracked belts.  Check  adjustment.  Proper  adjustment  for fan belt is a deflection of 9/32 inch with application of  12-14  lb  pressure  midway  between  fan  and accessory drive pulley. The alternator drive belt is adjusted  properly  when  there  is  9/64  inch  deflec- tion with application of 3–5 lb pressure midway between  alternator  and  accessory  drive  pulley. Replace  filter  elements. Clean  fuel  strainer. Change lubricating oil and filter. (Refer to LO.) Inspect for damage. Clean breather and tube at oil change  interval. Clean  air  cleaner  element  whenever  necessary  as indicated  by  air  filter  condition  indicator  light. Replace any broken or cracked lenses or defective bulbs. Check  for  cuts,  breaks,  frayed  wires,  or  damaged plug. Check security of mounting. Inspect ring for excessive  wear. Inspect  for  broken  links  or  missing  chain(s). 4-10