Arizona Air Brakes CDL Practice Test

What happens during stab braking?

1. Press on the brake pedal all the way

2. Release the brakes when the wheels lock up

3. Apply the brakes when the wheels start rolling

4. All of the above

The correct answer is: All of the above

Stab braking is a technique used to stop a vehicle in an emergency situation, especially when driving large vehicles equipped with air brakes. The correct answer encompasses all elements necessary for effective brake application in such scenarios. When utilizing stab braking, the driver first firmly presses down on the brake pedal to achieve maximum braking force. This initial application is crucial as it rapidly slows the vehicle. However, it is also important to monitor wheel lock-up; if the wheels were to lock due to excessive braking, releasing the brakes is essential. This allows the wheels to start rolling again, which helps maintain steering control and can prevent skidding. After the wheels start to roll again, the driver should reapply the brakes as necessary to continue reducing speed safely until a stop is achieved. This technique provides a blend of maximum braking effort while retaining control of the vehicle, which is why all steps are included in the correct answer.