TM 5-5420-234-14&P
5-2. DIRECT SUPPORT TROUBLESHOOTING.
1.
HOOK ARM DOES NOT UNLOAD.
INITIAL SETUP
Tools and Special Tools
Union, Pipe to Tube (GAH20-1/4 NPT-V)
Adapter, Straight, Pipe to Tube (TCM20-1/2JIC-V)
Wrench, Combination, 1-1/4 in. (GGG-W-636)
Gage, Pressure, Dial Indicating (151469)
Hose Assembly, Nonmetallic (HFF20-060)
Equipment Condition
Pan, Drain, 4-gallon (MIL-P-45819)
BAP unloaded to ground (para 2-10)
Tee, Tube (203102-8-8S)
Engine turned off (TM 9-2320-279-10)
Tool Kit, General Mechanic's: Automotive
Parking brake applied (TM 9-2320-279-10)
(SC 5180-90-N26)
Wheels chocked (TM 9-2320-279-10)
START
1.
KNOWN INFO
TEST OPTIONS
Unit
troubleshooting
Does the hook arm
completed.
unload
when
the
REASON FOR QUESTION
Other LHS functions OK.
hydraulic
control
solenoid is manually
During normal operation, the direc-
POSSIBLE PROBLEMS
bypassed?
tional control valve spool is actu-
ated by an electric solenoid. If the
Directional control valve faulty.
solenoid is faulty, the control valve
Hook
arm
manifold
will not operate. Operating the
counterbalance valve(s) faulty.
valve manually determines if the
hydraulic portion of the valve is
operating correctly.
NO
Go to Step 2.
Replace directional
control valve (para 5-
YES
