Abs Operation; Abs Self Check - Navistar ProStar+ Operation And Maintenance Manual

ABS Operation

To prevent property damage, personal injury,
and / or death, if the ABS warning indicator
comes on, have the ABS repaired immediately as
stopping distances may increase under certain
braking conditions.
prevent wheel lockup, which could result in loss
of vehicle control.
ABS requires no changes in driving practices. For the best
stopping performance with or without ABS, modulate – do
not pump – the brake pedal until the vehicle slows to desired
speed or stops. Be aware that ABS on a towing vehicle does
not control brakes on towed vehicles. Towed vehicles may
or may not have ABS. ABS will prevent lockup of controlled
wheels if you over-brake for existing road conditions. Optimum
vehicle control for existing road conditions will be provided as
a result of the ABS preventing wheel lockup at speeds above
approximately 4 miles per hour. The ABS cannot provide any
better braking and steering capability than the available road
traction will permit. If the road is slippery it will take longer
to stop than on a dry road. Steering maneuverability will be
similarly limited. Vehicle speed must be reduced to compensate
for the extended time and distance required to stop or slow the
vehicle on slippery roads.
The wheel hubs carry exciter rings used by axle mounted
sensors to transmit wheel speed information to the ABS
electronic control unit located inside the cab. The control unit
monitors and compares all wheel speed inputs to determine if
WARNING
Take every precaution to
any wheel(s) are about to lock. If wheel lockup is about to occur,
the control unit commands the appropriate modulator valve to
adjust air pressure delivery to prevent wheel lockup.

ABS Self Check

Bendix ® ABS Checkout: A YELLOW warning indicator on
the instrument panel indicates the antilock system status. The
indicator comes on and the system goes through an ABS
self-checkout sequence each time the ignition is turned on.
The system is working normally when ignition is turned on,
indicator comes on, then flashes twice and remains on for
several seconds before going out.
During the self-checkout, the modulator valves will cycle around
the vehicle twice in the following pattern
1. Right Front
2. Left Front
3. Right Rear
4. Left Rear
A fault has been detected in the ABS if the warning indicator
does not come on with ignition, does not flash, fails to go off, or
comes on again at any other time.
If over-braking causes wheel lockup on the rear drive axles
while engine braking devices are in operation, the ABS will
interrupt and disable the engine brake until the lockup situation
has stopped.
If the ABS warning indicator on the instrument panel is lit,
consult your nearest International Truck service center for
further assistance in maintaining and repairing your ABS.
Operation
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