PowerBoss Nautilus Hi-Dump PB45HDSL, Service Booklet

Page: 107 / 117

Adjusting the Nautilus neutral sensing switch
Purpose:
Floor damage can occur by operating the scrub brushes when the vehicle not in motion.
To prevent floor damage a neutral sensing switch shuts off and raises the scrub brushes and turn off the
solution flow whenever the vehicle remains motionless for more than 2 seconds.
When vehicle motion resumes the scrub brushes automatically turn on and lower and the solution flow
is turned on.
Operation:
The neutral sensing switch is a normally open roller switch located below and inboard of the pump
centering unit (Hydroback unit 731181).
The switch is activated by a cam attached to the pump centering arm.
Adjustment:
NOTE: Directional control (neutral) must be set before performing this adjustment.
Do not attempt to adjust the switch by bending the switch roller arm.
1. Slightly loosen the neutral switch mounting fasteners so that the switch can be repositioned by
hand.
The adjustment can be monitored by listening to the sound of the switch as it opens and closes.
2. Begin the adjustment by moving the switch body so that the roller fits up into the half-round cut
out in the cam. This is the neutral position and the switch should be open.
Insure that the switch body is kept level during adjustment. If the left end of the switch body is tilted up
it can cause the switch roller arm to bend during operation.
3. Adjust the switch body so that that a very small amount of pump arm motion will force the
roller down and close the switch.
Quick switch activation when the vehicle moves forward is more important than when the
vehicle moves in reverse so the adjustment should be made while pushing the pump arm
slightly forward by hand (towards the front of the vehicle) and then releasing the arm while
listening for the switch to close and open.
It is important that the switch reacts quickly otherwise it will be necessary to drive the vehicle at too high
a speed before the brushes become activated.
4. Insure that the switch also closes and opens when the pump arm is pushed slightly to the rear
and released.
5. Tighten the switch fasteners and retest.
CMK 10-28-2014