4-211. APU SECONDARY FUEL FILTER
This task covers:
c. Follow-on Maintenance
Tool Kit, General Mechanics, Automotive
Main Engine Shutdown (see para 2-12.)
(Appendix B, Section III, Item 1)
APU Shutdown (see para 2-16.)
Batteries Disconnected (see para 4-114.)
Diesel Fuel (Item 41, Appendix E)
Secondary Fuel Filter (Figure 212, Appendix E)
Due to the precise tolerances of diesel injec-
tion systems, it is extremely important the fuel
be kept clean. Dirt or water in the system can
cause severe damage to both the injection
pump and the injection nozzle.
When removing or installing drain plug on fuel
filter, use two wrenches in combination for
breaking plug loose and for final tightening.
(1) Remove drain plug (1) and drain secondary fuel filter (2).
(2) Remove bolt (3) and washer (4).
(3) Remove secondary fuel filter (2).
(1) Clean filter mounting area and moisten filter
gasket with diesel fuel (Item 41, Appendix E).
(2) Install new secondary fuel filter until gasket touches
mounting base then tighten 1/4 to 1/2 turn.
(3) Install bolt (3) and washer (4).
(4) Install drain plug (1).
c. Follow-on Maintenance.
(1) Connect batteries (see para 4-114).
(2) Prime fuel system and start and operate APU (see para
2-1 6) and check for leaking. Tighten filter
in small increments till leaking ceases.