TM10-3930-660-20 5-16. FUEL FILTER HEAD -  SERVICE/REPLACE This task covers: a. Service of filter elements b. Removal c. Installation Initial Setup Tools Materials/Parts Tool Kit, Automotive Mechanics Filters  (1)  (4) Seals (6) (7) (11) (12) Shop Equipment, Automotive Maintenance and Repair, Common #l Less Power Equipment  Condition Vehicle parked on level ground. SERVICE OF FUEL FILTER ELEMENTS l. DRAIN PRIMARY  FILTER  ELEMENT  (1). Drain primary fuel filter when water is present  in  fuel/water  separator  or after 50 hours of operation. Be sure fuel tank is at least 1/4 full. a. b. c. Open drain (2) at base of primary filter element (l). Operate hand lever on fuel transfer pump (3) until all water is drained from primary filter element (1) and only diesel fuel is  present. Close drain (2) at base of primary filter element (1). 5-35