PowerBoss Nautilus Hi-Dump PB45HDSL, Service Booklet

Page: 99 / 117

1
NAULTILUS SCRUB BRUSH FLOOR PRESSURE ADJUSTMENT
Note: the following 12 steps are required only for the factory or if you are replacing the reduction valve
730702 in port 4.1. If the part number on the side of the reduction valve body (not the coil but the
cartridge body) ends with the number 45 then it is already set at 450 psi and the following 12 steps can
be skipped.
Before the scrub head floor pressure adjustment can be performed the reduction valve at the main
hydraulic manifold port 4.1 must be adjusted to 450 psi (The purpose of this valve is to change the
variable inlet pressure (approximately 700 psi) to a constant output pressure of 450 psi which is applied
to the piston-end of the scrub head lift cylinder. 450 psi is the pressure required to raise the scrub head
at full engine rpm).
If this valve has already been adjusted go to “Setting the scrub brush floor pressure controller”.
To adjust the reduction valve at port 4.1:
1. Install a tee fitting with a gauge port between the main hydraulic hose and the hydraulic
manifold at port BLA.
2. Attach a suitable hydraulic pressure gauge to the gauge port in the tee fitting.
3. Zero the pressure gauge if necessary.
4. Loosen the lock nut on the adjustment stud on the reduction valve located on the main
hydraulic manifold at port 4.1
5. Insure that the green “One-Touch” switch is in the off position.
6. Start the engine
7. Set the throttle switch to high.
8. Turn the reduction valve adjustment stud clockwise until the pressure gauge reads 450 psi.
(Note: It is not possible to attain 450 psi if the restrictor orifice fitting is not installed at the
power steering unit pressure port.)
9. Tighten the reduction valve locknut.
10. Verify the pressure reading.
11. Turn off the engine.
12. Replace the hydraulic hose at port BLA.