Air Brakes Test Kentucky (2024) - FREE CDL Practice Test

1. Which of the following is NOT TRUE? When you drive a tractor-trailer combination with ABS, you should:

monitor your tractor and trailer as you slow down, and if it is safe to do so, back off the brakes to stay in control.
use only the braking force necessary to stop safely.
drive slower to keep your vehicle in a straight line.
brake the same way, regardless of whether you have ABS on the tractor, the trailer, or both.

2. If your ABS fails:

your tires might grab unexpectedly and you could lose control.
you will still have normal brake functions.
you will have no brake function, and could lose control.
the first step is to get the vehicle off the road and stop.

3. The supply pressure gauges tell you how much air pressure:

is in the air brakes.
is in the air tanks.
is going to the brake chambers.
you are applying to the brakes.

4. With a fully-charged air system, the leakage rates should be less than:

3 psi for single vehicles and 4 psi for a combination of two vehicles.
5 psi for single vehicles and 10 psi for a combination of two vehicles.
5 psi for single vehicles and 4 psi for a combination of two vehicles.
2 psi for single vehicles and 3 psi for a combination of two vehicles.

5. You are coming down a long, steep downgrade. Which of the following is a sign that your brakes may have started to fade?

The brake pedal feels spongy or goes to the floor.
You hear a loud "bang".
You have to apply your brakes harder and harder to get the same stopping power.
The steering feels heavy.

6. What is the best way to test the low air pressure warning signal?

step on and off the brake pedal while the engine is running.
Shut the engine off when you have enough air pressure, turn the electrical power on and step on and off the brake pedal to reduce air pressure to below 60 psi.
pump the brakes until the air pressure drops below 45 psi.
All of the above.

7. Too little weight on the driving axles can cause:

8. The air tanks should be drained completely to remove:

9. Before driving a vehicle with a dual brake brake system, the driver should:

pump the brake pedal 10 times to build pressure.
wait at least 10 minutes before driving.
allow time for the air compressor to build up a minimum of 100 psi pressure in both the primary and secondary systems.
wait at least 5 minutes before driving.

10. Which of the following is NOT correct? An ABS system:

reduces the braking pressure to a safe level.
helps you stop faster.
is a safety anti-skid braking system.
helps you avoid wheel lock up.

AIR BRAKES CDL PRACTICE TEST - KENTUCKY