We know that taking the air brakes test as part of your CDL permit can cause anxiety in even the most confident driver. That is why we designed this free air brake CDL test so that you can practice and get an idea of what types of questions will be asked on the actual test at the DMV. We encourage you to take it as many times as you would like or until you get a perfect score. We hope that this practice test proves helpful as you study for your exam. Please visit us again and take all of our practice exams as often as you would like.

Air Brake Test 03

1 / 25

Braking at 15 mph on dry pavement, you will take how much further to stop with air brakes than you would with hydraulic brakes?

2 / 25

If the air compressor develops a leak, what keeps the air in the tanks?

3 / 25

The first maneuver in 'stab braking' is to...?

4 / 25

ABS brakes will help you to...?

5 / 25

If your brakes are very hot from a long downgrade, you should avoid...?

6 / 25

When braking with a manual transmission, you should not press the clutch in until the engine RPM is...?

7 / 25

When braking on downgrades...?

8 / 25

You should test the compressor governor cut in and cut out pressures with the engine running at...?

9 / 25

To reach a speed 5 mph below your 'safe' speed on a downgrade should take around...?

10 / 25

If your ABS malfunctions, you should...?

11 / 25

When you have chosen a 'safe' speed for descending, you should try to keep your speed between it and...?

12 / 25

If you only have ABS on your trailer and you start to lose control of the tractor steering, you should...?

13 / 25

If you only have ABS on your tractor and your trailer starts to swing out, you should...?

14 / 25

Repeatedly pressing and releasing (FANNING) the pedal may result in a loss of air pressure.

15 / 25

Which of these is a factor in braking with air brakes which does not apply to hydraulic brakes?

16 / 25

If your brakes are very hot, or are wet when the temperature is freezing, instead of using the parking brake you should...?

17 / 25

Which of these is the most important factor in descending a downgrade safely?

18 / 25

You are driving a vehicle at 55 mph on dry pavement under good traction conditions. What is the approximate total stopping distance needed to bring your vehicle to a complete stop?

19 / 25

To test the parking brake, you should apply it and...?

20 / 25

For a normal stop with air brakes, you should...?

21 / 25

While making a controlled braking stop, your steering adjustments should be...?

22 / 25

If your wheels lock up, you must be aware that after you release the brakes it can take up to how long for the wheels to start rolling again?

23 / 25

Your brakes will overheat and start to fade if...?

24 / 25

Braking with air brakes from a 55 mph on dry pavement will add how much to your total stopping distance compared to hydraulic brakes?

25 / 25

Front wheel braking is good under all conditions.

Your score is


Air Brake CDL Test

Steps to take to get a CDL air brake endorsement:

The first thing you will have to do is pay a fee to apply for the air brakes endorsement before you can take the written knowledge Air Brakes CDL Test .

Book a practical test
The next step is to book a practical test appointment. To do that, you will need a valid driver’s license number, a preferred location for taking the test, a second and third choice of location and a preferred date. If you are not sure whether to take the test or not, you can cancel or reschedule the test appointment.

There are three types of CDL classes that determine the type of vehicle you may drive and how much you may tow. A Class A CDL class allows you to operate a vehicle with a GCWR of 26,001 if the vehicle you tow weighs more than 10,000 and a Class B CDL allows you to operate a vehicle with a GVWR of 26,001 or more pounds or operate any vehicle towing another vehicle that weighs less than 10,000 GVWR. With a Class C CDL, you can operate a Class C vehicle that transports hazardous materials.