TM 9-2320-366-34-1
2-1095
FOUR WAY CONTROL VALVE ASSEMBLY
FLOW TEST
NOTE
If hoist suddenly loses power, when not
overloaded, or fails to shut down, when
overloaded, relief valve RV1 is faulty. Clean
or replace RV1.
To test in hoist-down position substitute port B
for port A, in steps (2), (3), (14) and (15) and in
step (8) operate hoist-down.
(10) Stow MHC (TM 9-2320-366-10-1).
(11) Position MHC power to OFF (TM
9-2320-366-10-1).
(12) Position PTO switch to off (TM
9-2320-366-10-1).
(13) Shut down engine (TM 9-2320-366-10-1).
(14) Disconnect hydraulic tester, hose and adapters
from port A and hose.
(15) Connect hose to port A.
WARNING
Wear approved eye protection when performing
pressure checks. Failure to comply may result
in oil getting into eyes. If oil contacts eyes, seek
medical attention immediately.
Drop hydraulic pressure to zero before
disconnecting any hydraulic hose, tube, or fitting.
Failure to comply may result in injury to personnel.
Fuel and oil are slippery and can cause falls.
Wipe up spilled fuel or oil with rags. Failure
to comply may result in injury to personnel.
If hoist will only work in hoist down position,
perform visual inspection of winch-up lockout
valve. Replace damaged winch-up lockout valve.
If necessary, perform electrical system
troubleshooting (TM 9-2320-366-20-2).
(1) Place drain pan under vehicle.
(2) Disconnect hose from port A of hoist control
valve.
(3) Connect hydraulic tester between hose and
port A with test hoses and adapters.
(4) Start engine (TM 9-2320-366-10-1).
(5) Position PTO switch to on (TM
9-2320-366-10-1).
(6) Increase engine RPM to 1250-1450 RPM (TM
9-2320-366-10-1).
(7) Position MHC power switch to ON (TM
9-2320-366-10-1).
(8) Operate MHC to raise a moderate load with
hoist (TM 9-2320-366-10-1).
(9) Observe reading of about 9 gpm (34 lpm). If
flow is low, replace control valve in four way
(upper) control valve assembly.
