TM 5-5420-234-14&P
5-2. DIRECT SUPPORT TROUBLESHOOTING (continued).
6.
MAIN FRAME, HOOK ARM, AND WINCH DO NOT OPERATE OR OPERATE
SLOWLY (continued).
RELIEF VALVE TEST
(1) Replace relief valve (para 5-26).
(2) Start engine and engage the PTO.
(3) Turn the light control switch to the
STOP LIGHT position. Place LHS
MODE SELECT switch in the HOOK
ARM ONLY (manual mode) position.
(4) Attempt to operate the LHS and/or
winch using the remote control or cab
controls.
CAUTION
Fully extending or retracting
hydraulic cylinders will put the
hydraulic system into relief. This
should be limited to 10 seconds.
Failure to comply with this
warning may result in damage
to equipment.
NOTE
HYDRAULIC
Full relief pressure of 3,100 to
CABINET COVER
3,300 psi will be reached during
the full extension of the hydraulic
cylinder.
(5) Observe the readings on the pressure
gage during loading.
(6) Shut off engine and turn the light
control switch to the OFF position.
(7) Remove hose adapter, hose, and
pressure gage from main hydraulic
block assembly
(8) Install plug and O-ring in port TPP on
main hydraulic block assembly.
RELIEF
VALVE
MAIN
HYDRAULIC
BLOCK
5-43
