TM 9-2350-256-34-2
Table 2-3. Troubleshooting--Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
FUEL TRANSFER PUMP (AUXILIARY HYDRAULIC SYSTEM)
33. FUEL TRANSFER PUMP DOES NOT OPERATE
Step 1.
Inspect all hydraulic hoses and connections for visible indication of oil leaks.
Repair leaks or replace hydraulic hose. Refer to TM 9-2350-256-20, Medium Recovery Vehicle, M88A1.
Step 2.
Inspect system selector valve lever for improper position.
Place system selector valve lever in REFUEL position.
WARNING
Test components must be capable of withstanding a working pressure of 1450-1550 psi (Step 3 only).
Step 3.
Test for broken drive mechanism or faulty auxiliary hydraulic pump. Disconnect auxiliary hydraulic pump discharge hose no. 12. Install
suitable gate valve, in conjunction with pressure gage, to outlet of auxiliary hydraulic pump.
When restricting oil flow, operating pressure should be 1450-1550 psi.
CAUTION
When performing auxiliary hydraulic pump pressure test, do not restrict oil flow beyond operating pressure.
Remove auxiliary power unit from vehicle, and replace broken auxiliary hydraulic pump drive mechanism parts, or
faulty auxiliary hydraulic pump. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
Step 4.
Test for faulty or improperly adjusted relief valve within system selector valve. Install pressure gage in system
selector valve gage port. With auxiliary power unit operating, and auxiliary power unit (APU) emergency winch
control valve lever placed in CLOSED position, place system selector valve lever in AUX position, and adjust relief
valve.
a. Adjust relief pressure to 1450-1550 psi. For location of valve gage port, and adjusting screw, refer to view D, figure 3-20.
b. Replace system selector valve if pressure cannot be adjusted to 1450-1550 psi. Refer to TM 9-2350-256-34-1, Medium Recovery
Vehicle, M88A1.
Step 5.
Inspect impact wrench hoses for connection to outlets in compartment.
Disconnect impact wrench hoses.
Step 6.
Inspect fuel transfer pump for broken or damaged shaft coupling. Repair or replace shaft coupling. Refer to TM
9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
Step 7.
Inspect adjustable flow regulator lever for improper setting, or faulty adjustable flow regulator.
a. Refer to TM 9-2350-256-10, Medium Recovery Vehicle, M88A1 for proper setting.
b. If adjustable flow regulator lever is properly set, and fuel transfer pump does not operate, replace adjustable flow regulator. Refer to
TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
Step 8.
Inspect fuel transfer pump control valve lever for improper position, or faulty control valve.
a. Refer to TM 9-2350-256-10, Medium Recovery Vehicle, M88A1 for position.
b. If fuel transfer pump control valve lever is properly positioned and fuel transfer pump does not operate, replace fuel transfer pump
control valve. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
Step 9.
Inspect fuel transfer pump hydraulic motor for oil leaks or unusual noise. Remove shaft coupling from fuel transfer
pump and hydraulic motor. Operate auxiliary hydraulic system and inspect output shaft of hydraulic motor for
rotation in both directions.
a. If hydraulic motor shaft does not operate in both directions, replace hydraulic motor. Refer to TM 9-2350-256-34-1, Medium Recovery
Vehicle, M88A1.
b. If hydraulic motor leaks oil, or is noisy, replace hydraulic motor. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
Step 10.
Inspect fuel transfer pump for unusual noise or fuel leaks.
a. If fuel transfer pump is noisy, or leaks, replace fuel transfer pump. Refer to TM 9-2350-256-34-1, Medium
Recovery Vehicle, M88A1.
b. If fuel transfer pump is not noisy, or does not leak, and still fails to operate, replace fuel transfer pump. Refer to TM 9-2350-256-34-1,
Medium Recovery Vehicle, M88A1.
Change 2
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