SERVICE PERSONNEL HEATER FUEL PUMP/ELECTRIC FUEL PUMPS FLOW TEST --
M548A1 electric fuel pumps are located just inside power plant upper rear access door.
M548A3 electric fuel pumps are located on left side box beam in engine compartment.
There are two types of electric fuel pumps: the Bendix/Facet and Walbro. Both models are
tested the same way. The Bendix/Facet is shown.
Disconnect left fuel pump outlet hose (1) from fuel pump adapter (2) and hold hose over container.
(H) Turn MASTER SWITCH ON and fuel pump switch ON (see your -10).
Measure fuel flow for one minute. Fuel flow should be 1 1/4 to 2 1/2 quarts per minute (1.2 to 2.5 lpm).
Put end of outlet hose (1) into container of fuel. If air bubbles appear on surface, there is an air leak on suction side of
(H) Turn MASTER SWITCH OFF (see your -10). Tighten hose connections between fuel compartment and electric fuel
pump if needed. Remove left rear and right forward fuel compartment access covers (WP 0163 00). Clean screens at end
of each tube. Remove any blockage from pickup tubes. Use cleaning compound.
(H) Turn MASTER SWITCH ON (see your -10). Check fuel flow. Fuel flow should be 1 1/4 to 2 1/2 quarts per minute
(1.2 to 2.5 lpm). If not, replace electric fuel pump (WP 0149 00).
(H) Turn MASTER SWITCH OFF and fuel pump switch OFF (see your -10).