TM-9-2815-220-24
AVDS-1790 2CA, 2DA and 2DR Air-Cooled 12-Cylinder Diesel Engines
TECHNICAL MANUAL; UNIT, DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL FOR AVDS-1790 2CA, 2DA and 2DR Air-Cooled 12-Cylinder Diesel Engines
TM-9-2815-220-24 - Page 145 of 1563
TM 9-2815-220-24
FUEL SYSTEM ABNORMAL CONDITIONS
0020 00
MALFUNCTION 4:
In-tank fuel pump deficiencies.
PROBABLE CAUSE
CORRECTIVE ACTION
a. Electric circuit defective or electric motor
failure.
(1) Check operation as follows:
PROCEDURE
OBSERVATION
ANALYSIS
Electric pump operation is
audible (left and right fuel tanks).
Pump(s) is operative.
Open top grilles.
Turn
master switch and in-tank
fuel pump switch to "ON".
Pump(s) operation is not audible.
Pump(s) is inoperative.
PROBABLE CAUSE
CORRECTIVE ACTION
(2) Check electric circuit (refer to pertinent
vehicle technical manual). Repair as
required.
a. (Continued)
Electric circuit defective or
electric motor failure.
(3) Replace pump assembly (refer to pertinent
vehicle technical manual).
b. Pump output insufficient (defective pump or
screen clogged).
(1) Check pressure and output as follows:
PROCEDURE
OBSERVATION
ANALYSIS
Pump Operational Check
Electric pump operation is
audible (left and right fuel
tanks).
Pump(s) is operative.
Open top grilles.
Turn master
switch and in-tank fuel pump
switch to "ON".
Pump(s) operation is not
audible.
Pump(s) is inoperative.
Pump Fuel Pressure Check
Install pressure test gauges:
100 psi gauge in fuel/water separator filter cover bleeder valve
opening (WP 0084, Fuel/Water Separator Automatic Drain
System and Wiring Harness Replacement).
10 psi gauge in primary filter cover bleeder valve opening
(WP 0086, Primary Fuel Filter Replacement).
Turn master and in-tank fuel
pump switches "ON".
Less than 5 PSI at both
fuel/water separator and
primary fuel filters.
In-tank pump is operative.
Operate engine at high-idle
speed (2500-2640 rpm).
Zero psi at fuel/water
separator filter, and zero psi at
primary fuel filter.
In-tank pump(s) inoperative
or fuel line restriction.
Pump Output Check (Fuel Flow Capacity):
Open left grille doors.
Disconnect fuel tank supply hose quick-
disconnect coupling valve at engine.
Open coupling valve (hold open) to collect fuel in suitable
container (5 gallon).
Turn master and in-tank fuel pump switches "ON".
WP 0020 00-3
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