TM 9-2350-256-34-2
Table 2-3. Troubleshooting--Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
HOIST WINCH CIRCUIT (MAIN HYDRAULIC SYSTEM)-Continued
10. HOIST WINCH PAYS IN BUT WILL NOT PAY OUT
Step 1.
Remove hoist winch brake cover. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1, and check if hoist winch brake is
releasing.
Adjust brake. Refer to TM 9-2350-256-20, Medium Recovery Vehicle, M88A1.
Step 2.
Remove hydraulic brake cylinder hose no. 28 and inspect for restriction
Replace restricted or damaged hose. Refer to TM 9-2350-256-20, Medium Recovery Vehicle, M88A1.
Step 3.
Remove hoist winch brake cylinder and test for malfunction. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
Replace hoist winch brake cylinder.
Step 4.
Adjust counterbalance valve. Refer to paragraph 3-21.1.
Replace counterbalance valve if defective. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
11. HOIST WINCH PAYS OUT BUT WILL NOT PAY IN
Step 1.
Inspect for restricted pilot hose between hoist winch control valve and combination control valve. Refer to fig. FO-5 and trace pilot circuit.
Replace restricted or damaged pilot hose. Refer to TM 9-2350-256-20, Medium Recovery Vehicle, M8A1.
Step 2.
Broken free-wheeling ratchet brake assembly unit in hoist winch
a. Remove hoist winch assembly. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
b. Replace hoist winch Refer to paragraph 3-19.
12. HOIST WINCH CREEPS IN EITHER DIRECION WHEN IN HOLD POSITION
Step 1.
Inspect for restricted pilot hose or hoist winch control valve. Refer to figs. FO-4 and FO-5 and trace hose and valve for restriction.
a. Replace any restricted pilot hose. Refer to TM 9-2350-256-20, Medium Recover Vehicle, M88A1.
b. Remove restriction or replace control valve. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
NOTE
In cold weather, oil viscosity increases, causing a retarded flow of oil and possibly causing winch to creep. Proper warm-up will correct
13. HOIST WINCH WILL NOT HOLD LOAD
Step 1.
Inspect hoist winch brake for proper adjustment
Adjust hoist winch brake. Refer to TM 9-2350-256-20, Medium Recovery Vehicle, M88A1.
Step 2.
Remove hoist winch brake cover and inspect for worn brake lining. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, MS88A1.
Replace brake lining. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
Step 3.
Defective counterbalance valve.
Replace counterbalance valve. Refer to TM 9-2350-256-34-1, Medium Recovery Vehicle, M88A1.
14. INSUFFICIENT MAIN SYSTEM OIL PRESSURE
Step 1.
Test mechanical transmission clutch pressure. Install pressure gage in mechanical transmission clutch pressure hose. 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 15010 psi.
a. Remove mechanical transmission and main hydraulic pump assembly. Refer to TM 9-2350-256-34-1, Medium
Recovery Vehicle, M88A1.
b. Replace mechanical transmission. Refer to paragraph 3-16.
Change 5
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