TM 9-2350-256-34-2
Table 2-3. Troubleshooting-Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
MAIN WINCH CIRCUIT (MAIN HYDRAULIC SYSTEM)-Continued
7. LEVELWINDER NOT OPERATING
Step 1.
Inspect hoses and fittings for visible indication of oil l
eaks. Repair or replace hoses and fittings. Refer to paragraph 3-9.
Step 2.
Inspect level winder valve spool and cylinder rod for leaks.
a. Remove main winch and spade assembly. Refer to TM 9-2350-256-34-1. Medium Recovery Vehicle, M88A1.
b. Replace level winder. Refer to paragraph 3-9.
Step 3.
Inspect level winder control valve actuating mechanism for broken parts.
a. Remove control valve actuating mechanism. Refer to TM 9-2350-256-34-1. Medium Recovery Vehicle. M88A1.
b. Repair control valve actuating mechanism. Refer to figure 3-14.
8. LEVEL WINDER NOT OPERATING PROPERLY
Step 1.
Inspect level winder for improper adjustment (evident by uneven wrap of cable).
Adjust level winder assembly. Refer to TM 9-2350-256-20, Medium Recovery Vehicle. M88A1.
HOIST WINCH CIRCUIT (MAIN HYDRAULIC SYSTEM)
CAUTION
Close auxiliary power unit emergency winch control valve for main hydraulic system operation.
9. HOIST WINCH WILL NOT OPERATE
Step 1.
Attempt operation of main winch, boom and spade.
If main winch, boom and spade operate, proceed to step 9.
If main winch, boom and spade do not operate, proceed to step 2.
Step 2.
Inspect mechanical transmission drive shaft.
If not rotating, repair or replace. Refer to TM 9-2350-256-34-1. Medium Recovery Vehicle. M88A1.
Step 3.
Inspect mechanical transmission for broken restricted hose.
Replace mechanical transmission hose. Refer to TM 9-2350-256-20. Medium Recovery Vehicle, M88A1.
Step 4,
Inspect mechanical transmission outfit shaft. If not rotating.
proceed with mechanical transmission clutch pressure check. Install
pressure gage in mechanical transmission clutch pressure line. For location, refer to TM 9-2350-256-20, Medium Recovery Vehicle,
M88A1.
With engine operating at 1800 rpm, and power control valve lever in ON position, normal operating pressure is 150
10 psi.
a. Remove mechanical transmission and main hydraulic pump assembly. Refer to TM 9-2340-256-34-1, Medium Recovery Vehicle,
M88A1.
b. Replace mechanical transmission. Refer to paragraph 3-16.
Step 5.
Test for defective power control valve. Remove hose No. 66 from valve. With power control valve level in ON position, and mechanical
transmission input shaft rotating, oil should flow from valve port. Replace power control valve. Refer to TM 9-2350-256-34-1, Medium
Recovery Vehicle. M88A1.
Step 6.
Inspect main hydraulic pump for broken or damaged shaft coupling.
a. Remove mechanical transmission and main hydraulic pump assembly. Refer to TM 9-2350-256-34-1, Medium
Recovery Vehicle,
M88A1.
a. Repair or replace shaft coupling. Refer to paragraph 3-16.
WARNING
Test components must be capable of withstanding a working pressure of 1950-2050 psi (Step 7 only).
NOTE
After performing main hydraulic pump test. return all plumbing to original configuration.
Step 7.
Test main hydraulic pump Remove check valve and tee between hose no. 4A and 4B. Install main hydraulic pump pressure tester kit
(Item 14., Table 2-1I between hose no ,4A and hose no. 4B. Install test pressure gage in tee.
Change 5
2-9
