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 cdl practice test air brakes 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.
The brake pedal in an air brake system controls the air pressure applied to the brakes.

Question 1 of 25

The modulating control valve allows you to control the...?

Question 2 of 25

Which of these is not part of an air brake system?

Question 3 of 25

All air brake equipped vehicles have Air supply pressure gauge.

Question 4 of 25

During the walk-around inspection, if a slack adjuster moves slightly more than an inch where the push rod attaches to it, then...?

Question 5 of 25

Air brakes use what to function?

Question 6 of 25

The most common type of foundation brake found on heavy vehicles is the...?

Question 7 of 25

If the pressure drops at higher than the recommended rate when the engine is turned off and the parking brake released, it could be indicative of...?

Question 8 of 25

Which of the following statements are true?

Question 9 of 25

Spring brakes...?

Question 10 of 25

Truck tractors with air brake systems will definitely have ABS if built after March 1...?

Question 11 of 25

Separate air tanks to release the spring brakes when the main air brake system has failed should only be used...?

Question 12 of 25

Emergency brake systems use...?

Question 13 of 25

Service brakes are activated by...?

Question 14 of 25

In air brake vehicles, the parking brakes should be used...?

Question 15 of 25

A modulating control valve can be used to apply spring brakes...?

Question 16 of 25

With the engine off and the parking brake released in a combination vehicle, the pressure should not drop by more than how many PSI per minute?

Question 17 of 25

If the air pressure does not build fast enough after turning the engine on, you should...?

Question 18 of 25

The main purpose of the alcohol evaporator is to put alcohol in the air system.

Question 19 of 25

With your engine at operating RPM, in a dual air system the pressure should build from 85 to 100 psi within...?

Question 20 of 25

If you push the brake pedal down when the spring brakes are on, you are risking...?

Question 21 of 25

The air compressor runs off...?

Question 22 of 25

In newer vehicles, parking brakes are controlled using a diamond shaped control knob of what color?

Question 23 of 25

Once the air system is fully charged and you have turned off the engine and released the parking brake, in a single vehicle the pressure should not drop by more than how many PSI per minute?

Question 24 of 25

What protects the tank and the rest of the air system from too much pressure?

Question 25 of 25



CDL Practice Test Air Brakes

Air brake endorsement course
At this stage of air brake endorsement, there are two versions of the airbrake endorsement courses that are normally provided. One of them is the By vehicle fleet owners course. Drivers will need to go for a 12-hour course if they are upgrading to class AZ license. Drivers holding class B, C, D, E, F or G licenses and wishing to get a Z endorsement will go for the 10.5-hour course.

The other version of the airbrake endorsement course is By community colleges and safety organizations. Drivers upgrading to class A (Z) license will go for a 12-hour course.

After successfully completing the endorsement course, you will get a referral envelope. This is the envelope expected at the DriveTest center normally within a period of 6 months before you get a CDL air brake endorsement. Try our free CDL practice test air brakes now we have 110 questions in our online database.

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.