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TITLE
SYSTEM RELIEF VALVE
TESTING AND ADJUSTMENT
WARNING: Always retract wings fully,
lower the plow to the ground and re-
lieve pressure before removing any
fittings, hoses or caps. Allow the system to
cool down before draining oil or handling
system components. Serious burns can re-
sult from contact with hot oil. FAILURE TO
HEED CAN RESULT IN SERIOUS INJURY OR
DEATH.
TEST CONDITIONS
WARNING: Vehicle engine must be
running for this procedure. Make sure
that there is adequate ventilation in
test area and/or that vehicle exhaust is vent-
ed outside of test area building. FAILURE TO
HEED CAN RESULT IN SERIOUS INJURY OR
DEATH.
- Vehicle battery is fully charged.
- Hydraulic oil level is to “Fill Line.”
PROCEDURE
Park vehicle in an area with adequate ventila-
tion and with enough room to safely raise the
plow. Set park brake. Retract wings fully and
lower the plow to the ground. Remove pump
cover.
PHOTO NO. 4130
Carefully disconnect the hydraulic fitting from the
port marked “L” on the front of the valve block.
Using the proper fittings, install a pressure gauge
as shown.
Start the vehicle. Activate and hold the Raise
switch on joystick control box. Record the
pressure reading.
A change in pitch from the hydraulic motor
should be heard and a pressure of 2250 PSI
+/- 100 should be indicated on the pressure
gauge.
If pressure readings are high or low, refer to
the following adjustment procedures.
ADJUSTMENT
PHOTO NO. 4133
WARNING: Always lower the plow and
relieve pressure before removing any
lines or caps.
Remove the hex cap located on the right hand
side of the valve block assembly. See photo
4133.
The slotted screw underneath the cap is for ad-
justing the relief valve pressure setting. Turning
the screw clockwise increases the pressure and
turning the screw counterclockwise decreases
the pressure. Turn the screw in 1/4 turn incre
-
ments until the pressure gauge indicates 2250
PSI +/–100.
System Relief Valve Testing and Adjustment 29