Table 2-3. Troubleshooting--Continued
TEST OR INSPECTION
HYDRAULIC IMPACT WRENCH (AUXILIARY SYSTEM)
34. IMPACT WRENCH DOES NOT OPERATE
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.
Inspect system selector system valve lever for improper position.
Place system selector valve lever in REFUEL position.
Test components must be capable of withstanding a working pressure of 1450-1550 psi (step 3 only)
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 to auxiliary hydraulic pump.
When restricting oil flow, operating pressure should be 1450-1550 psi.
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.
Test for faulty or improperly adjusted relief valve within the 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
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 impact wrench does not operate, replace adjustable flow regulator. Refer to TM 9-
2350-256-34-1, Medium Recovery Vehicle, M88A1.
Inspect fuel transfer pump control valve lever for improper position.
Place fuel transfer pump control valve lever in CLOSED position.
Inspect impact wrench for oil leaks or unusual noise.
a. If impact wrench leaks oil, or is noisy, replace impact wrench.
b. If impact wrench does not leak oil, or is not noisy, and still fails to operate, replace impact wrench.