RECOVERY VEHICLE, FULL TRACKED: MEDIUM, M88A1
HOISTING BOOM CIRCUIT (AUXILIARY HYDRAULIC SYSTEM) TROUBLESHOOTING PROCEDURE
Tools and Special Tools
Hoisting Boom Circuit (Auxiliary Hydraulic System)
Hoisting boom circuit (auxiliary hydraulic system) malfunctioning.
Boom will not operate.
Inspect all hydraulic hoses and connections for visible indication of oil leaks.
Repair leaks or replace hydraulic hose (TM 9-2350-256-20).
Inspect system selector valve lever for improper position.
Place system selector valve lever in AUX position.
Inspect APU emergency winch control valve lever for improper position.
Place the APU emergency winch control valve lever in CLOSED position.
Test components must be capable of withstanding a working pressure of 14501550 psi (999810,687
kPa) (step 4 only).
Test for broken drive mechanism or faulty auxiliary hydraulic pump. Disconnect auxiliary hydraulic
pump discharge hose no. 12. Install suitable gate valve, in conjunction with pressure gage, to outlet
of auxiliary hydraulic pump. When restricting oil flow, operating pressure should be 14501550 psi
When performing auxiliary hydraulic pump pressure test, do not restrict oil flow beyond operating
Remove APU from vehicle, and replace broken auxiliary hydraulic pump drive mechanism parts, or