TM 9-2350-256-34-2
Table 2-3. Troubleshooting-Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 9.
Step 10.
Step 11.
Step 12.
Step 13.
Step 14.
Step 15.
22. SPADE WILL NOT HOLD WITH SPADE COMBINATION CONTROL VALVE LEVER IN ANY POSITION
SPADE CIRCUIT (MAIN HYDRAULIC SYSTEM) - Continued
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 valve lever for improper position.
Place system selector valve lever in MAIN position.
Inspect auxiliary power unit (APU) emergency winch control valve lever for improper position.
Place auxiliary power unit (APU) emergency winch control valve lever in CLOSED position.
WARNING
Main winch must be in high range (step 12 only).
Test for faulty pilot-operated relief and unloading valve. Attempt operation of boom and winches, If winches
operate. but boom and spade fail to operate. it indicates a faulty pilot-operated relief and unloading valve. Shift
main winch into high range and inhaul cable completely (clevis contacting front of plate). Continue holding main
winch control lever in this position and attempt to operate spade combination control valve lever. Release both
levers to neutral and operate spade combination control valve lever.
If the spade does not function. replace pilot-operated relief and unloading valve. Refer to TM 9-2350-256-34-1.
Medium Recovery Vehicle, M88A1.
Test for spade combination control valve failure. Install pressure gage in pilot operated relief and unloading
valve gage port. If, when actuating boom combination control valve lever, operating pressure (1950-250 psi)
is recorded on pressure gage, but when actuating spade combination control valve lever, on pressure is re-
corded on gage; it indicates a faulty spade combination control valve. For location of valve gage port, refer
to view B, fig. 3-22.
Replace spade combination control valve. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
Test for restricted or blocked cylinder return hose. Install pressure gage in pilot operated relief and unloading
valve gage port If, when actuating spade combination control valve lever, operating pressure (1950-2050 psi)
is recorded, return hose is restricted or blocked. For location of valve gage port, refer to view B, fig 3-22.
Remove any restriction or replace blocked hose. Refer to TM 9-2350-256-20, Medium Recovery Vehicle, M88A1.
Test for mechanical failure of hydraulic cylinders. Install test gage in pilot operated relief and unloading
valve gage port. If, when actuating spade combination control valve lever,
operating pressure (1950-2050 psi)
is recorded and no return hose is blocked, it indicates mechanical failure of a hydraulic cylinder. For location
of valve gage port, refer to view B, fig 3-22.
II. Remove main winch and spade assembly. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
b. Replace spade cylinder. Refer to paragraph 3-6.
Step 1. Test for spade combination control valve failure.
Install pressure gage in pilot operated relief and unloading
valve gage port If, when actuating boom combination control valve lever,
operating pressure (1950-2050 psi)
is recorded on pressure gage, but when actuating spade combination control valve lever, no pressure is re-
corded on gage; it indicates a faulty spade combination control valve. For location of valve gage port, refer
to view B, fig. 3-22.
Replace spade combination control valve. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
Step 2. Worn spade hydraulic cylinder packings.
a. Remove main winch and spade assembly. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle. M88A1.
b. Replace spade cylinder. Refer to paragraph 3-6.
Step 3. Ruptured hydraulic hose.
Replace hydraulic hose. Refer to TM 9-2350-256-20, Medium Recovery Vehicle, M88A1.
Step 4.
Damaged spade release valve.
Replace spade release valve. Refer to TM 9-2350-256-20.
2-16
Change 7
