Preparing for the Ontario Air Brake test can be a daunting task, but with our free practice tests, you can gain the confidence and knowledge needed to pass the exam on your first try.

These practice tests include questions and scenarios that are similar to those you will encounter on the actual test.


Ontario Air Brake Test 01

1 / 30

In an air brake system, what purpose does the alcohol evaporator serve?

2 / 30

Many vehicle manufacturers recommend draining moisture and oil from a vehicle's air tanks at what interval?

3 / 30

Which of these vehicles is most likely to have air brakes?

4 / 30

Which of these can you expect from an air brake system that you will not get in a hydraulic brake system?

5 / 30

Spring brakes will normally start to apply when system pressure drops below...?

6 / 30

Which of these persons can perform brake readjustments on manual and automatic slack adjusters?

7 / 30

When draining tanks on an air brake system, which tank should be drained first?

8 / 30

Why do air brake systems have dual-service tanks?

9 / 30

Under the Ontario Highway Traffic Act, an air brake system should never drop below what pressure?

10 / 30

The air compressor for an air brake system draws its power from where?

11 / 30

Moisture in an air brake system can be dangerous for what reason?

12 / 30

Where will you find air brake chambers?

13 / 30

Spring brakes are applied when...?

14 / 30

In an air brake system, the service brake subsystem is used for what?

15 / 30

Normal air brake system pressure range is around…?

16 / 30

Which is the only one of these that is part of a disc brake system?

17 / 30

Where will you find the air pressure gauge for an air brake system?

18 / 30

If an air brake system has an air dryer, where will it be found?

19 / 30

The supply tank for an air brake system does what?

20 / 30

In a normal braking situation, most modern air brake vehicles will use automatic valves to do what?

21 / 30

The spring brake subsystem is designed for which of these?

22 / 30

The pushrod stroke is produced by compressed air entering...?

23 / 30

A braking system works by converting mechanical energy into what?

24 / 30

If you are driving and a warning tells you that your air pressure is low, what should you do?

25 / 30

At what pressure do safety valves on air brake systems normally open?

26 / 30

The air tanks for an air brake system can be found where?

27 / 30

Why is it important for you to know where compressed air from the air brake system on your vehicle exhausts?

28 / 30

A warning device must alert the driver if the pressure in the air brake system falls to what level?

29 / 30

As you press down on the brake pedal, what happens to the valve which is attached to it?

30 / 30

In an air brake system, what does the governor do?

Your score is


Ontario Air Brake Practice Test

Our free Ontario Air Brake practice test questions and answers will prepare you to pass Ontario’s official Air Brakes knowledge test. To begin your career in trucking, you must obtain your Ontario Class A or Class D Truck Driver’s Licence. The appropriate CDL endorsements you will need are based on the type of trucking career you plan to pursue. To obtain these endorsements, you must complete a written knowledge test successfully. Making sure you are adequately prepared for your written knowledge test will prevent you from wasting time and money. Taking practice CDL tests is the best way to get ready.

Passing your air brake test doesn’t have to be a stressful experience. Follow this important tip, and you should pass the test without a problem.

Start Preparing Early – Don’t try to cram the night before. Give yourself a few weeks to study the materials, such as this Ontario air brake practice test. Trying to learn all the information in a couple of days will only cause unneeded stress and anxiety during test time. Relax, take your time, and study at a comfortable pace.