108
Service Manual – SC8000
108
Hydraulic System
Functional Description
Overview
The hydraulic system powers the drive wheel motor, scrub brushes, vacuum fan and side brush/brooms (if
the machine is so equipped). The hydraulic system also actuates the main scrub deck and side brush/broom
lift cylinders, the squeegee lift cylinder and the drive wheel steering assembly.
The engine drives the two hydraulic pumps that send the hydraulic oil to the various components:
• The main piston (propulsion) pump (1.44 CIR) is a variable-displacement pump that powers the drive
wheel.
• The dual-displacement, low-speed (accessory) pump is actually two separate pumps in one unit (1.20 and
0.58 CIR) and powers the other machine components.
A system of electrically-controlled solenoid valves directs the hydraulic oil to the various system components
to perform the needed scrubbing/sweeping and solution recovery functions.
Note:
The electrical wiring diagrams/schematics use an “
L
” followed by a number to identify the
solenoid (coil) portion of a solenoid valve. The hydraulic schematic uses an “
S
” followed by a
number to identify the corresponding cartridge (hydraulic valve). This pairing of numbers is
used to establish the connection between the solenoid coils and their corresponding hydraulic
valves. For instance, solenoid coil
L6
is mounted on hydraulic valve
S6
and controls
hydraulic valve
S6
.
