Antilock Braking System (Abs); Air System Emergency Fill Valve - PREVOST Motorcoach XL Series Operator's Manual

NOTE:
Each time the parking brake is applied
and ignition key is turned or left to the "ON"
position, the stoplights automatically light up.
ANTILOCK BRAKING SYSTEM
(ABS)
(Optional)
The purpose of the antilock braking system is to
preserve the stability and steerability of a vehicle
during braking, and to minimize its stopping
distance whatever the road conditions.
On slippery roads and in emergency situations,
overbraking frequently induces wheel locking.
Antilock braking system provides maximum
braking performance while maintaining adequate
steerability on slippery roads.
Also, on smooth or slippery surfaces, the stopping
distance with locked wheels is greatly extended;
on rough surfaces however the problem is tire
abrasion.
ABS constantly monitors wheel behavior during
braking. Sensors on each wheel of front and drive
axles continually monitor the wheel speed during
braking, transmitting
four-channel electronic processor which senses
when a wheel is about to lock. Modulating valves
quickly adjust the brake pressure (up to 5 times
per second) to prevent wheel from locking. Each
wheel is thereby controlled according to the grip
available between its tire and the road.
In this way the vehicle is brought to a halt in the
shortest possible time, while remaining stable and
under driver's control.
CAUTION:
On slippery roads, motorists behind
you may not be able to brake as fast as you; so
whenever possible, give a prior warning by lightly
depressing brake pedal several times before
braking.
this information to
AIR SYSTEM
FILL VALVE
The vehicle is equipped with two air system
emergency fill valves to supplement the air
system when air pressure is low and engine
cannot be operated. The rear valve is located in
engine compartment and is accessible from
engine R.H. side door: On XL-40 vehicles, the
valve is positioned next to battery booster block,
close to door hinge; on XL-45 vehicles, the valve
is positioned directly under back up alarm, close
to L.H. side of door opening.
a
FIGURE 66: XL-40 Rear valve location
FIGURE 67: XL-45 Rear valve location
The front valve is located in the steering
compartment close to R.H. side of door frame.
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SAFETY
EMERGENCY
12057
12011