Scrub System
176
Service Manual – Advance 7765 / Nilfisk CR1500
Problem
Cause
Correction
Scrub deck not
being raised to the
retracted position.
Scrub Brush Solenoid (6)
not opening when energized
(stuck closed).
1. Check the coil resistance of the Scrub Brush
Solenoid (6). If the coil resistance is not 9.8 ohms
±10%, replace the coil.
2. If the coil resistance is within spec, check for
binding or a mechanical problem. Repair or
replace the valve as necessary.
Scrub Brush Solenoid (8)
not opening path from top
of Scrub Deck Cylinder to
reservoir return when de-
energized (stuck open).
1. Check the coil resistance of the Scrub Brush
Solenoid (8). If the coil resistance is not 9.8 ohms
±10%, replace the coil.
2. If the coil resistance is within spec, check for
binding or a mechanical problem. Repair or
replace the valve as necessary.
Specifications
Component Specifications
Component
Specifications
Normal Rotation Brush (4)
Solenoid
Reverse Rotation Brush
(6) Solenoid
Initial Current Draw – 1.67 amps
Nominal Coil Resistance – 7.2 ohms
Scrub Brush Solenoid (6)
Scrub Brush Solenoid (8)
Scrub Brush Lock Up
Solenoid (9)
Initial Current Draw – 1.22 amps
Nominal Coil Resistance – 9.8 ohms
Scrub Brush Motors
Displacement – 10 CIR