F - Air Antilock Brake System Fundamentals Flashcards
List two advantages when braking a vehicle equipped with antilock brakes.
Directional stability and control.
Decreased stopping distances.
Braking is most effective when the rotation of the wheel and tire is slowed:
Without overcoming friction between the tire and the road.
The antilock air brake system modulates (?) to slow the vehicle effectively and under control.
Brake application pressure.
Antilock brake systems can modulate brake application pressure up to (?) times per second.
100
List the basic components of an antilock system.
Tone wheel, speed sensor, ECU, ABS indicator lamp, and brake modulator valve.
A modulator valve is in the air lines to each front wheel and to the right driving tandems and the left driving tandems. What type of ABS system is this?
4S 4M
The purpose of the tone ring is to:
Induce electrical pulses in the speed sensor.
The antilock system’s ECU is a computer that:
Analyzes and processes speed sensor signals and controls vehicle speed limitations.
A vehicle is being driven with the ABS indicator light illuminated. This indicates to the driver that:
There is an antilock system malfunction.
If the antilock system fails during vehicle operation, the standard brake system will:
Function normally.
The tone rings are most commonly mounted to the:
Wheel hubs.
On a tandem drive axle truck chassis with one modulator valve for each side, the modulator valve controls:
Two brake chambers.
If arc welding must be performed on a vehicle with antilock, the ECU should be:
Unplugged or disconnected.
When removing the hub assembly from an antilock equipped vehicle, a technician must:
Take care not to damage the tone ring and sensor. Support and block the vehicle safely.
A wheel speed sensor is positioned by:
Pushing the sensor in until it touches the tone wheel.
