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

1. To prevent rollover, you should:

place the cargo near the rear of the trailer.
place the cargo near the front of the trailer.
keep the cargo as close to the ground as possible.
put the lightest parts of the cargo under the heaviest parts.

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

drive slower to keep your vehicle in a straight line.
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.
brake the same way, regardless of whether you have ABS on the tractor, the trailer, or both.

3. If you must stop on a one-way or divided highway, place your warning devices:

10 feet, 50 feet, and 150 feet toward the approaching traffic.
50 feet, 100 feet, and 150 feet toward the approaching traffic.
100 feet, 200 feet, and 300 feet toward the approaching traffic.
10 feet, 100 feet, and 200 feet toward the approaching traffic.

4. Air tank drains:

should not be used in wet weather.
are used to remove water and oil from the air tanks.
protect the tanks and the rest of the system from too much pressure.
are used to move air to the brakes.

5. A tank endorsement is:

required for both liquids and gases.
only required when transporting liquids.
only required when transporting gases.
not required when transporting hazardous materials.

6. You supply air to the trailer brake system by:

pushing in the trailer air supply knob.
connecting the tractor service air line to the trailer service glad hand.
pulling out the trailer air supply valve.
plugging the electrical cord into the trailer.

7. With the air pressure built up to governor cutoff, the maximum leakage rates per minute after the initial pressure drop are:

1 psi for single vehicles and 2 psi for a combination of 2 vehicles.
4 psi for single vehicles and 2 psi for a combination of 2 vehicles.
3 psi for single vehicles and 4 psi for a combination of 2 vehicles.
5 psi for single vehicles and 6 psi for a combination of 2 vehicles.

8. Empty trucks have the best braking. True or False?

9. To apply the parking brakes:

push the parking brake control knob in.
place the parking brake control knob in Neutral.
push the brake pedal three times.
pull the parking brake control knob out.

10. If the low pressure warning signal doesn't work:

in dual systems the stopping distance will be decreased.
you could lose air pressure and you would know it.
this could cause sudden emergency braking in a single-circuit air system.
None of the above.

AIR BRAKES PRACTICE TEST - MINNESOTA