TM 5-3805-280-24-2
Fuel System Operation and Tests
115
NOTE: When operating hand primer, a moderate
44
resistance should be felt. When only a slight
resistance (or no resistance) occurs, replace hand
primer or repair pump (valves may be defective).
3. Operate hand primer until fuel flows from pump outlet
(discharge). Fuel should flow within 15--25 strokes. If
not, the suction line may be obstructed or leaking air;
(replace in-line filter when used).
If fuel does not flow, and if no leak or obstruction is
found, pump is defective. Repair or replace pump.
(See Group 35).
Test operation of discharge side of pump:
1. Suction line must be connected and discharge
(pressure) line disconnected.
2. Tighten hand primer and place injection pump fuel
shut-off control in "STOP" position to prevent engine
from starting.
3. Crank engine with starting motor. Fuel should flow from
pump outlet within 10 seconds. If not, the suction line
may be obstructed or leaking air; (replace in-line filter
when used).
Test pump output pressure while cranking engine:
1. Connect a 0--400 kPa (0--4 bar) (0--60 psi) pressure
gauge to one end of a pressure hose about 250--300
mm (10-- 12 in.) long. Connect other end of hose to
pump outlet. All air must be out of system.
IMPORTANT: The starting motor must crank the
engine at normal cranking speed. Use
booster batteries if necessary.
2. Crank engine for 10 seconds with starting motor
(approximately 300 engine rpm).
3. Compare measured output with the minimum pressure
specifications.
Continued on next page
RG,115,JW7702
1924NOV972/3
13-571
