RECOVERY VEHICLE, FULL TRACKED: MEDIUM, M88A1
SPADE CIRCUIT (MAIN HYDRAULIC SYSTEM) TROUBLESHOOTING PROCEDURE
Tools and Special Tools
Spade Circuit (Main Hydraulic System)
Spade circuit (main hydraulic system) malfunctioning.
Spade will not operate.
Do steps 1 thru 15.
Spade will not hold with spade combination control valve lever in any position. Do steps 16 thru 19.
Spade will operate only partially. Do steps 20 thru 23.
Attempt operation of main winch, hoist winch, and boom.
If main winch, hoist winch, and boom operate, proceed to step 13.
If main winch, hoist winch, and boom do not operate, proceed with step 2.
Inspect mechanical transmission drive shaft.
Inspect mechanical transmission for broken or restricted hose.
Replace mechanical transmission 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
location, refer to TM 9-2350-256-20. With engine operating at 1800 rpm and power control valve lever
in ON position, normal operating pressure is 150 10 psi (1034 69 kPa).
Remove mechanical transmission and main hydraulic pump assembly (WP 0065 00).
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).