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 air brakes practice 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 01

1 / 30

An air compressor governor will resume pumping air to the tanks when tank pressure falls below around...?

2 / 30

The brake system that applies the use of the brakes when the driver uses the brake pedal is the ______ brake system?

3 / 30

On vehicles made before 1975, if the front brake limiting valve control is switched to 'slippery' the air pressure to the front brakes will be cut by...?

4 / 30

Air compressor governors are programmed to cut out when air pressure reaches around...?

5 / 30

The resistance you feel when you push the brake pedal down comes from...?

6 / 30

Spring brakes are usually fully activated when the air pressure is between...?

7 / 30

When the low air pressure warning light or buzzer comes on, you should...?

8 / 30

If the spring brakes are on you should push the brake pedal.

9 / 30

Safety relief valves on the first tanks are usually set to open at...?

10 / 30

On large buses, it is common for low-pressure warning devices to activate at around...?

11 / 30

Emergency brakes and parking brakes on all large vehicles must be operated by...?

12 / 30

Which of these brake systems uses a 'power screw'?

13 / 30

An air pressure system is fully charged at _____ P.S.I.?

14 / 30

The application pressure gauge shows...?

15 / 30

Brakes can stop working if...?

16 / 30

Supply pressure gauges on an air brake system tell you...?

17 / 30

The low air pressure warning signal on an air brake system must come on before the air pressure falls below...?

18 / 30

The stoplights on an air brake system are activated by...?

19 / 30

When air is pumped into a brake chamber, what is the first thing that happens?

20 / 30

The most common sort of emergency and parking brake on large vehicles is...?

21 / 30

Foundation brakes can be found on...?

22 / 30

In a wedge brake system, a push rod pushes a wedge directly...?

23 / 30

The air compressor should stop pumping at about ____ P.S.I.

24 / 30

Pumping the brake pedal up and down unnecessarily can result in...?

25 / 30

Air brake systems are three braking systems combined. They are:

26 / 30

Many vehicles have automatic front wheel limiting valves, which will reduce air to the front brakes unless they are applied with a pressure of greater than...?

27 / 30

If application pressure increases without a decrease in speed, you need to...?

28 / 30

Air tanks should be drained to clear them of...?

29 / 30

You should drain air tanks at the end of...?

30 / 30

Drum brakes work by pressing brake shoes and linings against...?

Your score is


Study CDL Air Brakes Practice Test and Applying for the for the Air Brake endorsement

When applying for the Air Brake endorsement taking a written test, the first thing to do is to verify that you meet the requirements for sitting for the written test. You should then verify the amount of fees you are required to pay as you apply.

You should then fill up the air brake endorsement written test application then turn it in. Schedule an appointment for the skills test. This should only be done after you are comfortable and ready for the test. To be ready, make sure you read the CDL handbooks and take this CDL air brakes practice test to find out if you’re ready for the actual written test.

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.

Eligibility for CDL Air Brake Test

CDL Air brakes practice testYou will, of course, need to have some driving skills before you seat for a CDL air brake test. Then you will need to have an understanding of the braking supply system. In this case, you need to understand that air is pumped into the braking supply system from the atmosphere. You should know how it passes through filters and dries before it is stored in the main reservoir.

To be eligible for the CDL air brake test, you should understand how air is maintained and the constant pressure to drive under. The constant pressure is normally around 125 psi. Maintenance will be needed for the pressure mounts at 150 psi.

You should have an understanding of the parking brake. This is a safety feature of an air brake system. This is a spring-actuated brake that prevents the vehicle from moving. It is normally engaged by default. The air that mounts in the braking system pulls the spring open and disengages the brake.

To be eligible for the air brake endorsement on your CDL, you must have the basic knowledge of other parts of a truck that power the brakes other than just the compressed air. It is important to understand that pedals and the gearbox system use compressed air to amplify and assist the input of the driver.

The cost of a CDL air brake endorsement
normally, there is a fee charged by the state Department of Public Safety and Correctional Services for the HAZMAT background record check. The TSA processing fee and the state and federal background checks have been reduced to $88.75. It is also important to understand that there is a fee charged for correcting a CDL or adding an endorsement. However, no charges will apply if you were required to obtain a commercial learner’s permit.