MAINTENANCE
71
8400D MM312 (2–94)
THERMO SENTRY
The Thermo Sentry
senses the temperature of
the air pulled up from the hopper. If there is a fire
in the hopper, the Thermo Sentry
stops the
vacuum fan and cuts off the air flow.
Reset the Thermo Sentry
by pushing in its reset
button.
SCRUB HEAD
The scrub head encloses the scrub brushes and a
solution dispensing system. The scrub head is
located directly behind the sweeping brush
compartment.
The scrub head is factory adjusted and the
measurement should not be changed unless
scrub head parts are damaged or are replaced.
BRUSHES
MAIN BRUSH
The main brush is cylindrical and spans the width
of the machine, sweeping debris into the hopper.
Check the brush daily for wear or damage.
Remove any string or wire tangled on the main
brush, main brush drive hub, or main brush idler
hub.
Check the main brush pattern daily. The pattern
should be 50 to 65 mm (2.0 to 2.5 in) wide with
the main brush in the lowered position. Adjust the
main brush pattern by turning the main brush
pressure knob located next to the brush position
lever.
Rotate the main brush end-for-end every 50 hours
of operation for maximum brush life and best
sweeping performance.
Replace the main brush when the remaining
bristles measure 25 mm (1 in) in length.
