TM 5-5420-234-14&P
5-2. DIRECT SUPPORT TROUBLESHOOTING (continued).
1.
HOOK ARM DOES NOT UNLOAD (continued).
3.
TEST OPTIONS
KNOWN INFO
Counterbalance Valve
Unit troubleshooting
Does the hook arm
Test.
completed.
unload after the
Other LHS functions OK.
counterbalance valves
REASON FOR QUESTION
Directional control valve
are reversed on the
OK.
left hook arm cylinder
If the hook arm cylinder
manifold?
manifold counterbalance
POSSIBLE PROBLEMS
valve(s) stick in the closed
Hook arm manifold
position, hydraulic fluid will
counterbalance valve(s)
be trapped in the hydraulic
faulty.
cylinder, which will hydro-
lock the cylinder.
Repair RH hook arm
cylinder manifold
NO
Repair LH hook arm
cylinder manifold
YES
5-8
