TM 10-3930-641-34-1
HYDRAULIC SYSTEM TROUBLESHOOTING (CONT)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
9. CONTROL VALVE SEALS LEAK
Step 1. Check for foreign material under the seal.
a.
Clean valve.
b.
Replace seals. (See page 7-44.)
Step 2. Check for worn or damaged seals.
Replace seals. (See page 7-44.)
Step 3. Check valve spools for wear or damage.
Replace spools. (See page 7-44.)
Step 4. Check for looseness of seal plates.
Tighten plates. (See page 7-44.)
10. THE LOAD LOWERS WHEN LIFT LEVER IS MOVED FROM NEUTRAL TO RAISE POSITION
Step 1. Check for foreign material in check valve.
Clean. (See page 7-44.)
Step 2. Inspect check valve for wear on poppet and seat.
Replace poppet and seat. (See page 7-44.)
11. THE HYDRAULIC SYSTEM WILL NOT HOLD A LOAD
Step 1. Check for oil bypass between valve and body.
Replace control valve. (See page 7-44.)
Step 2. Check for oil bypass between cylinder and piston.
Replace cylinder assembly. (See page 7-44.)
Step 3. Test spool for centering.
Replace that section. (See page 7-44.)
Adjust control linkage. (See TM 10-3930-641-20.)
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