FREE CDL Air Brake Anti-lock Braking Systems Questions and Answers

Question 1

What is the primary purpose of ABS on a vehicle?

Accepted Answer

To prevent wheel lock-up during hard braking.

Answer

The primary purpose of ABS (Anti-lock Braking System) is to prevent the wheels from locking up during hard braking. This allows the driver to maintain steering control and vehicle stability, especially on slippery surfaces. While it can sometimes reduce stopping distances, its main function is to prevent uncontrolled skidding and improve control.

Question 2

When driving a vehicle equipped with ABS, how should you apply the brakes in an emergency?

Accepted Answer

Apply the brakes firmly and hold them.

Answer

When driving a vehicle equipped with ABS, the correct emergency braking technique is to apply the brakes firmly and hold them down. The ABS system will automatically modulate the brake pressure to prevent wheel lock-up, allowing you to steer and stop safely. Pumping the brakes would interfere with the ABS's intended operation.

Question 3

What should you do if the ABS warning light stays on after you start your vehicle?

Accepted Answer

Get the ABS checked as soon as possible, but the service brakes will still work.

Answer

If the ABS warning light stays on, it indicates a malfunction in the Anti-lock Braking System. While the ABS itself may not be working, the vehicle's regular service brakes will still function normally, allowing you to stop. It is important to get the ABS checked by a mechanic as soon as possible to restore this important safety feature, but it does not require an immediate stop or tow.

Question 4

On which vehicles is ABS required by law?

Accepted Answer

All of the above.

Answer

Federal regulations mandate ABS on specific commercial vehicles to enhance safety. This requirement applies to trucks and buses manufactured after March 1, 1997, and trailers manufactured after March 1, 1998. Therefore, all the listed categories of vehicles are legally required to have ABS.

Question 5

How does ABS help in an emergency stop on icy or wet roads?

Accepted Answer

It prevents skidding and allows you to steer.

Answer

On icy or wet roads, ABS is crucial because it prevents the wheels from locking up during hard braking. By maintaining wheel rotation, ABS allows the tires to retain some traction, enabling the driver to steer the vehicle and avoid skidding. This significantly improves control and safety in hazardous conditions, rather than simply shortening stopping distances.

CDL Air Brake - Commercial Driver's License Air Brakes Test Practice Test

CDL Air Brake - Commercial Driver's License Air Brakes Test Practice Test

FREE CDL Air Brake Anti-lock Braking Systems Questions and Answers