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).
HYDRAULIC SYSTEM PRESSURE TEST
WARNING
The LHS hydraulic system operates at
oil pressures up to 3,625 psi (24,994
kPa). Never disconnect any hydraulic
line or fitting without first dropping
pressure to zero. Failure to comply
with this warning may result in serious
injury or death to personnel.
(1) Remove plug and O-ring from port TPP on
main hydraulic block assembly.
(2) Install hose adapter, hose, and pressure
gage on main hydraulic block assembly.
TEST PORT
HOSE
(3) Start engine and engage the PTO.
TPP
(4) Turn the light control switch to the STOP
LIGHT position. Place LHS MODE
SELECT switch in the HOOK ARM ONLY
(manual mode) position.
(5) Attempt to operate the LHS and/or winch
using the remote control or cab controls.
HOSE
ADAPTER
CAUTION
Fully extending or retracting hydrau-
lic cylinders will put the hydraulic
system into relief. This should be
limited to 10 seconds. Failure to com-
ply with this caution may result in
damage to equipment.
NOTE
Full relief pressure of 3,100 to 3,300 psi
GAGE
will be reached during the full extension
of the hydraulic cylinder.
(6) Observe the readings on the pressure gage
during loading.
(7) Shut off engine and turn the light control
switch to the OFF position.
NOTE
If 3,100 to 3,300 psi were not obtained,
skip the remaining steps in this test and
go to Step 3.
(8) Remove hose adapter, hose, and pressure
gage from main hydraulic block assembly
(9) Install plug and O-ring in port TPP on main
hydraulic block assembly.
5-41
