ARMY TM 9-6115-670-14&P 4-69 4.29.  FUEL SYSTEM. This task covers: Service INITIAL SETUP Tools General Mechanic's Tool Kit (Item 1, Appendix B) Gloves, Chemical and 0.1 Protective Equipment Conditions Engine stopped and allowed to cool completely. MASTER ON-OFF switch on APU control unit set to OFF. Materials/Parts None Personnel Required Two SERVICE a.  With the APU installed in the shelter, vehicle fuel line attached to fuel transfer pump, and fuel return line attached from day tank back to vehicle fuel tank, position MASTER ON-OFF switch to ON. b.  On APU control unit, position BATTLE SHORT switch to ON.  This will allow fuel transfer pump to override safety protection devices. c.  Allow pump to run until day tank has been filled (observe that LOW FUEL indicator on control unit goes out). d.  Open fuel bleed port (1, Figure 4-16) on the injection pump. WARNING Ensure that NO IGNITION SOURCE is within 50 feet of the 10 kW APU. The fuel in this APU is highly flammable. Do not smoke. Do not splash fuel on hot components. Failure to heed this warning could result in serious injury to personnel or DEATH. WARNING Avoid  fuel  contact  with  skin.  Wear  protective  gloves, goggles, apron and mask, while disconnecting fuel lines. Failure to this warning could result in serious injury to personnel or  DEATH. NOTE Service of the fuel system is accomplished by bleeding air out from the fuel system.  Bleeding the fuel system must be performed whenever a major component of the fuel system has been replaced or during service upon receipt to prime the system.  Normally, the APU will not need to be primed each time it is started. NOTE Use suitable container to catch purged fuel.