Ontario Commercial Drivers License Air Brakes Practice Test 4

Commercial Driver HQ is a website focused on helping new commercial drivers in all provinces and territories in Canada.

Our FREE practice tests are designed to help you succeed when it comes time to write the real test.

Each license type has 5 tests to help you study and become familiar with the rules and regulations of commercial driving. The tests are not identical to the license test you will need to pass, but the questions are similar to what you will find on the real deal.

Compatible on desktop, mobile, and tablet, you can take these tests anywhere you have internet access.

Take the practice test!

Created by

Commercial Driver HQ

Ontario Air Brakes Practice Test 4

A 20 question practice test to help prepare you for your air brakes knowledge test in Ontario

1 / 20

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

Drum

Rotors

Lining

Shoe

2 / 20

What is the most frequent reason a vehicle is removed from service?

Sleepy drivers

Tire treads

Over weight limits

Air brakes

3 / 20

Where is the air pressure gauge for the air brake system?

On each wheels brake

On the vehicle dashboard

Beside the air compressor

Beside the supply tank

4 / 20

What is not a factor in how well your air brake system works?

Weight of the vehicle

Brake adjustments

Weight of the driver

Driving speed

5 / 20

Correct belt tension for an air compressor can be determined by

Firm hand pressure

A karate chop

Finger pressure

A tight squeeze of the hand

6 / 20

What is a "glad hand"?

The crank for the trailer legs

A coupling device

A dance move

An emergency supply line

7 / 20

Who can perform adjustments and maintenance on your air brake system?

Your employer

You can if you are the owner

Only certified technicians

Anyone

8 / 20

How do you engage the emergency / parking brake on most air brake systems?

Twist it to the right

Pull out the control

Twist it to the left

Press down the pedal

9 / 20

Why are their two service tanks?

For fuel economy

For efficiency

For safety

Incase you need more stopping power

10 / 20

What can cause the air pressure in the air brake system to drop?

A broken air compressor

All of these

Disconnected supply line

A hole in the supply line

11 / 20

Which colour represent the trailer supply line?

White

Blue

Red

Yellow

12 / 20

Activation of trailer spring brakes can be checked by?

Gunning it

Rocking the truck back and forth

Pulling the trailer air valve

Applying slight engine power

13 / 20

What function does the alcohol evaporator perform?

Prevents freezing

Prevents moisture build ups in the brake lines

Prevents overheating

Prevents the system from building up too much pressure

14 / 20

A warning system must alert the driver when the pressure drops below?

413 kPa (60 psi)

380 kPa (55 psi)

242 kPs (35 psi)

551 kPa (80 psi)

15 / 20

When brakes become overheated they also become?

Dangerously inefficient

None of the above

Extra efficient

Very hot

16 / 20

What is an ABS system?

Automatically brakes when needed

Prevents wheel lock

Increases braking power

Reduces stopping distance

17 / 20

Cut out pressure level must never exceed __________.

1000 kPa (145 psi)

862 kPa (125 psi)

1138 kPa (165 psi)

690 kPa (100 psi)

18 / 20

How long should it take for the air pressure to rise from 587kPa to 690 kPa after the pressure had fallen below 552 kPa?

5 mins

1 min

2 mins

4 mins

19 / 20

Which of these vehicles would usually have an air brake system?

A school bus

A hearse

A compact car

A pickup truck

20 / 20

When inspecting an air brake system, the person inspecting should wear?

Shorts and Crocs

Sandals and shorts

Dust mask, safety glasses

Steel toe boots, safety glasses, hard hats

Thanks for taking the practice test!

Enter your info to sign up for our mailing list or click "See Result" to move on.

NameEmail

Your score is

The average score is 88%

More Ontario Commercial Driving Practice Tests

Ontario Class A Practice Tests

Ontario Class D Practice Tests

Air Brakes Practice Tests

Ontario Road Signs Test

We do our best to keep the questions current and accurate. The testing centres may change the questions on the knowledge tests at any time. Always be prepared for surprises.

Many of the answers to the questions can be found in the driver hand books or learning materials your province provides.

DISCLAIMER: CDHQ is not affiliated with DriveTest or the MTO. These practice tests should not be considered official tests and you are not granted a license for completing them. Our tests are simply a practice tool to help prepare yourself for the real test.