TM 5-3805-261-20
HYDRAULIC SYSTEM TROUBLESHOOTING AND MAINTENANCE PROCEDURES. (cont)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
b.
CIRCLE DRIVE OPERATES SLOWLY OR FAILS TO OPERATE.
Step 1.
Check the circle drive hydraulic hoses for leaks and loose
fittings.
If a circle drive fitting is loose--tighten. If a hose is damaged or defective--replace. Refer to paragraph 15-29.
Step 2.
Measure circle drive operation time. Using a stop watch, measure the amount of time for a one
quarter revolution.
The time for a one quarter revolution in either direction is between 9.5 and 11.5 seconds.
If the time recorded is not within this range--replace circle drive. Refer to paragraph 15-6.
If the time recorded is within range, a flow meter tee test should be performed. Contact Direct Support.
c.
BLADE FLOAT FAILS TO OPERATE.
Step 1.
Check the blade float hydraulic hoses for leaks and loose fittings.
If a blade float fitting is loose--tighten. If a hose is damaged or defective--replace. Refer to paragraph 15-25.
Step 2.
Check to see if it is one or both sides of the blade that do not float.
If both sides of the blade float do not operate--replace blade float pilot valve. Refer to paragraph 15-7.
If one side of the blade float does not operate--replace blade float check valve. Refer to paragraph 15-8.
15-4
