TM 10-3930-641-34-1
HYDRAULIC SYSTEM TROUBLESHOOTING (CONT)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
33. FLOW LOSS PERCENTAGE FOR TEST 12 IS 10% OR MORE. FLOW DIFFERENTIAL FOR TEST 12 IS MORE THAN 0 GPM HIGHER THAN THE FLOW
DIFFERENTIAL FOR TEST 14. TESTS 15 THRU 22 HAVE THE SAME FLOW DIFFERENTIAL.
TEE tests 12 and 14, and 15 thru 22. (See page 7-139.) Indicate oil aeration.
Step 1. Drain and fill system with correct oil.
Step 2. Correct leaks on low side of system (pump suction side).
Step 3. Disassemble pump and reassemble correctly.
34. IN TESTS 15 THRU 22, THE FLOW DIFFERENTIAL IS THE SAME FOR THE FIRST FEW TESTS, BUT SUDDENLY DROPS AT ONE OF THE TESTS
AND REMAINS THE SAME FOR THE REST OF THE TESTS. FOR EXAMPLE, TESTS 15, 16, AND 17 ARE THE SAME, BUT THE FLOW DIFFERENTIAL
DROPS AT TEST 18 AND STAYS THE SAME FOR TESTS 19 THRU 22.
TEE tests 15 thru 22. (See page 7-141.) Indicate pump cavitation.
Remove restriction in pump suction line.
35. TESTS 24 THRU 28 INDICATE LEAKAGE IN ONE OR MORE OF THE CYLINDERS. (SEE PAGE 7-145.)
TEE tests 24 thru 28. (See page 7-145.)
Do the BLOCKED RIGHT CYLINDER TEST. (See page 7-144.)
36. TESTS 24 AND 25 INDICATE LEAKAGE IN CONTROL VALVES.
TEE tests 24 and 25. (See page 7-145.)
Repair or replace the control valve. (See page 7-44.)
37. TEST 26 AND 27 INDICATE LEAKAGE IN CONTROL VALVE.
TEE tests 26 and 27. (See page 7-145.)
Repair or replace tilt control valve. (See page 7-44.)
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