LeeBoy LB Performance CB95 - Priority Relief Valve

Maintenance
LB Performance CB95 Broom5-20
Priority Relief ValvePriority Relief Valve
The priority ow divider in the hydraulic manifold is set
to supply the power steering with approximately 4 GPM
(15 LPM) of hydraulic ow. This ow goes to the steering
circuit before any other circuit.
The Priority Relief Valve controls the maximum oper-
ating pressure for the power steering, brush lift and
swing circuits. (Figure 5-18) This valve is located in the
hydraulic pump attached to the rear of the hydrostatic
pump on the engine ywheel.
These are signs the priority relief valve needs adjusting:
• Total or partial loss of steering functions or hard
steering.
• Constant noise from the hydraulic pump when using
steering or brush lift and swing.
• Hydraulic oil overheating.
Only an experienced technician
should service the hydraulic manifold (priority relief)
as death or serious injury can result from improper
valve adjustments. See your authorized LB Perfor-
mance dealer for assistance if experiencing steering
function issues or hydraulic oil overheating.
To adjust the priority relief valve:
1. Set the park brake and ensure the transmission is in
neutral. Use the foot brake as an extra precaution.
2. Plumb a 0 to 5000 PSI pressure gauge into the
priority ow circuit.
3. Start the engine and allow the hydraulic oil to warm
to at least 100° F.
4. Increase engine speed to 2500 RPMs.
5. Raise the brush until it stops, continuing to hold
pressure to the lift cylinder until a gauge reading
can be taken.
6. The pressure gauge should read 1500 +/- 50 PSI.
7. Adjust the relief pressure by removing the locknut
and turning the adjusting screw:
• Turn adjusting screw clockwise to increase
pressure.
• Turn adjusting screw counterclockwise to
decrease pressure.
GEAR PUMP
PRESSURE HOSE
TO STEERING
ORBITAL
PRIORITY
RELIEF VALVE
Figure 5-18. Hydraulic Manifold (Priority Relief)