Abs Brakes - PREVOST Motorcoach XL Series Operator's Manual

NOTE: Parking brakes can supplement service
brakes to stop the vehicle in an emergency
condition only. The stopping distance will be
considerably longer than with a normal brake
application.
Before releasing parking brakes by pushing down
control valve knob, pressure gauges should be
checked to ensure that brake system air pressure
has built up to a minimum of 95 psi (655 kPa).
WARNING: Always apply parking brake before
leaving driver's seat.
NOTE: Each time the parking brake is applied
and ignition key is turned or left to the "ON"
position, the stoplights automatically light up.
ABS BRAKES
braking system)
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 the problem is tire abrasion.
The basis of ABS is constant monitoring of the
wheel behaviour during braking. Sensors on each
wheel of front and drive axles continually monitor
the wheel speed during braking, transmitting this
information to a 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.
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.
(antilock
(Optional)
Each wheel is thereby
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.
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.
XL-40 rear valve location
XL-45 rear valve location
3 - 2
SAFETY
EMERGENCY
12057
12011