TM10-3930-660-20 5-16. FUEL FILTER HEAD   - SERVICB/REPLACE (Cont’d) 20 CHANGE PRIMARY (1) AND SECONDARY (4) FILTER ELEMENTS. a. Turn primary filter element (1) counterclockwise and remove from fuel filter head (5). b. Turn secondary filter element (4) counterclockwise  and  remove  from fuel filter head (5). c. d. e. f. g. h. i. j  . k. 1. Discard old filter elements (1) and (4). Remove and discard seals (6) and (7) from filter head (5). Clean fuel filter head (5) where filter elements (1) and (4) were attached. Install new seals (6) and (7) to filter  head  (5). Fill new filter elements (1) and (4)  with  clean  fuel.  Lubricate outer seals on filter elements (1) and (4) with clean oil. Turn secondary filter element (4) clockwise on fuel filter head (5) until  tight. Turn primary filter element (1) clockwise on fuel filter head (5) until  tight. Loosen hose (8) at fitting (9). Operate hand lever on fuel transfer pump (3) until fuel flowing from fitting (9) is free of air. Tighten hose (8) at fitting (9). 01 5-36