RECOVERY VEHICLE, FULL TRACKED: MEDIUM, M88A1
HOISTING BOOM CIRCUIT (MAIN HYDRAULIC SYSTEM) TROUBLESHOOTING PROCEDURE
Tools and Special Tools
Hoisting Boom Circuit (Main Hydraulic System)
Hoisting boom circuit (main hydraulic system) malfunctioning.
Boom will not operate.
Do steps 1 thru 15.
Boom operates partially.
Do steps 16 and 17.
Boom will not hold in any position.
Do steps 18 and 19.
Boom will not stop automatically after live boom operation. Do steps 20 and 21.
Boom live operation does not function. Do step 22.
Attempt operation of main winch, hoist winch, and spade.
If main winch, hoist winch, and spade operate, proceed to step 13.
If main winch, hoist winch, and spade do not operate, proceed with step 2.
Inspect mechanical transmission drive shaft.
Inspect mechanical transmission for broken or restricted hoses.
Replace any broken or restricted hoses (TM 9-2350-256-20).
Test for defective power control valve or restricted hose. Remove hose no. 66 from mechanical
transmission. With mechanical transmission drive shaft rotating and power control valve lever placed
in ON position, oil should flow from hose.
Replace restricted or damaged hose (TM 9-2350-256-20).
Inspect mechanical transmission output shaft. If not rotating, proceed with mechanical transmission
clutch pressure check. Install pressure gage in mechanical transmission clutch pressure line. For