TM 5-4520 -244-14
HOW TO TEST THE HEATER FUEL PUMP
- FLOW TEST -
Disconnect fuel tank end of bypass tube from fuel pump to tank,
Disconnect the tube which is right by the fuel tank cap,
Connect a flexible tube or hose to each of the tubes disconnected
in steps 2 and 3.
Obtain two containers, each able to hold at least one gallon, one
of them having a mark at the one-gallon line, Place ends of both
flexible lines into unmarked container,
Install the engine, Close heater outlet-air damper by loosening
knob and turning completely to the left,
Set the temperature selector indicator knob to 150-degrees F.
Start the heater, Readjust if necessary to get 150-degrees F on
When temperature is stable, transfer flexible hoses to the container
having a gallon mark, Measure the time for one gallon of fuel flow,
Stop the heater,
If it takes more than five minutes for the pump to deliver one gallon,
replace the pump,
Remove the engine.
Reconnect the fuel lines.
Install the engine,