PowerBoss Nautilus Hi-Dump PB45HDSL, Service Booklet

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1
OPTIONAL SIDE SCRUB BRUSH HYDRAULIC MANIFOLD OPERATION
The side scrub brush hydraulic manifold performs the following functions:
Side brush on and off
Side scrub head raise and lower
Side scrub head locked in the raised position
Side brush scrubbing force
Side brush extend and retract
Location and operation of the individual side scrub brush hydraulic valves:
The following single solenoid valve that controls side brush on-off function receives hydraulic pressure
and flow from port P2. This fluid is received downstream from the two main scrub brush motors. This
fluid originates from the front auxiliary pump which has a displacement of .84 cu. In./rev. and supplies a
nominal flow of 8.7 gpm.
Pressure relief is provided by relief valve RV1 in the main manifold. This valve allows a maximum
pressure of 2500 psi. This valve dumps to tank through port T2
SOLENOID VALVE SV8
(Side brush on-off) in port 7.2 is a 2-position 2-way normally-open control valve .
When de-energized this valve allows flow to bypass the side brush motor.
When energized this solenoid closes the bypass and directs pressurized flow to the side brush motor.
This valve directs the fluid flow to the motor through port MB-IN and back into the manifold through
port SB OUT then back to tank through port T2.
The following five side brush system solenoids receive hydraulic pressure from the center auxiliary pump
which has a displacement of .66 cu. In./rev. and supplies a flow of 6.8 gpm. This fluid comes from a tee
in the steering unit pressure port just below (upstream from) the orifice.
PROPORTIONAL REDUCTION VALVE SV9 (Side brush force) in port 6.2.
This valve controls side brush scrubbing force (against the floor) by regulating the fluid pressure to the
piston-end of the scrub head lift cylinder.
SOLENOID VALVE SV10 (Side brush down) in port 5.3 is a 2-position 3-way directional control valve .
When de-energized this valve directs flow from the piston-end of the side brush lift cylinder to tank.
When energized it directs regulated pressure to the piston-end of the side brush lift cylinder.
This valve directs the flow to the side brush lift cylinder through port SBLA.
REDUCING VALVE RV4 in port 4.2 limits the hydraulic pressure to the rod-end of the side brush lift
cylinder to a maximum of 450 psi.
SOLENOID VALVE SV11 (side brush up-locked) in port 3.2 is a 2-position 2-way normally-open control
valve.
When de-energized this valve allows flow into the rod-end of the side brush lift cylinder while
preventing flow out from the rod-end of the side bush lift cylinder (scrub head raise and lock).