FUEL PUMP CALIBRATION - CONTINUED
Fuel is flammable and can explode. To avoid serious injury or death, keep fuel away
from open fire and keep extinguisher within easy reach when working with fuel. Smoking
is prohibited while working with fuel.
Do not hold throttle in idle position any longer than necessary to complete test. Pump
may overheat, since fuel flow is used to cool the pump.
Pump must pick up fuel at 500 rpm without priming. If no fluid pickup is indicated at
rotameter, check fuel filter for improper installation and motor switch for correct
rotation, Make sure open suction valve, hose, and gear pump connections are tight.
Check rotameter for air in fuel flow. If air bubbles are present, work pump throttle lever
from fuel full open to idle several times, to relieve trapped air in pump.
If air bubbling persists, it is an indication of an air leak in the system. Turn test stand off
and check the line for loose connections between tank and pump, mating of gear pump
housing, and full fuel supply tank.
If pump is new or has been disassembled or reassembled, run pump slightly over rated
speed for 5 minutes to allow bearings and seals to seat, and to purge air from system.
24. Test stand (1)
Speed control but-
tons (14 and 15)
Start test stand by depressing start
button (18) until 2130 to 2150 rpm
is indicated on test stand
Depress and release FAST (14) or
SLOW (15) button to maintain 2130 to
At end of 5-minute period, reduce fuel
pump speed to 500 rpm.
T A 2 4 2 5 6 3