Skip to main content

Air brake endorsement (Code 15)

ICBC air brake knowledge test practice

Practise for the ICBC air brake endorsement (Code 15) knowledge test with original questions drawn from the air brake section of ICBC's Driving Commercial Vehicles guide. Every answer carries a clear, cited explanation, so you learn how an air brake system works rather than just memorising an answer key.

Start practising

Timed exam simulationPaidSit a full 25-question test against the clock, just like the real ICBC exam. Unlock it with a one-time upgrade.

Get the most from your practice

A one-time upgrade unlocks full-length tests and the timed exam simulation for every test on the site.

See upgrade options

Your scores are saved automatically. Sign in to sync them across devices.

What is the air brake endorsement, and who needs it?

The air brake endorsement, shown on a BC driver's licence as code 15, adds the privilege of operating a vehicle equipped with an air brake system. Air brakes use compressed air, rather than hydraulic fluid, to apply the brakes, and they work differently enough that a driver must demonstrate specific knowledge before driving an air-braked vehicle.

The endorsement is required for most large trucks and buses — many Class 1, 2 and 3 vehicles run on air brakes — and for some larger recreational vehicles. Whether you need it depends on the brake system the vehicle is fitted with, not on how the vehicle is used.

On-highway and industrial air brakes

Code 15 is the on-highway air brake endorsement, for vehicles driven on public roads. A separate industrial (off-highway) air brake endorsement covers air-braked vehicles used on logging and resource roads. Both are studied from the same Driving Commercial Vehicles guide.

What is the format of the air brake knowledge test?

The air brake knowledge test is a computer-based, multiple-choice test sat at an ICBC driver licensing office. Like every ICBC knowledge test, it uses an 80% pass mark.

  • 25 multiple-choice questions drawn from the air brake material in the Driving Commercial Vehicles guide.
  • 20 correct answers (80%) are needed to pass.
  • A 45-minute time limit.
  • The test is offered in English only — translators are not permitted.
  • If you do not pass, you must wait seven days before trying again.
  • After three failed attempts you must retake the air brake training course before testing again.

How this practice test is set up

Each practice attempt draws 25 questions and asks you to score 20 to pass, with a 45-minute timer in exam-simulation mode — the same numbers as the real ICBC air brake knowledge test.

What does the air brake test cover?

Questions are based on the air brake section of the Driving Commercial Vehicles guide. Our practice bank is organised into six topics that mirror that material.

  • How air brakes work — compressed air as a braking medium, brake lag, dual circuits and how the system fails to a safe condition.
  • Air brake components — the compressor, governor, reservoirs, check valves, brake application valve, brake chambers, slack adjusters and air dryer.
  • Inspecting air brakes — pre-trip checks, the leak-down (air loss) test, governor cut-in and cut-out checks, and testing the low-pressure warning.
  • Brake adjustment — pushrod travel, slack adjusters, measuring stroke and keeping the brakes within limits.
  • Using air brakes safely — making smooth stops, avoiding brake fade, and controlling speed on hills and downgrades.
  • Faults and emergencies — low-pressure warnings, spring (emergency) brakes, leaks and how to respond to an air system failure.

Is there a practical air brake test as well?

Yes. The air brake endorsement has two parts: the written knowledge test covered by this practice test, and a practical air brake test. Passing the knowledge test alone does not earn the endorsement.

In the practical test you carry out an air brake pre-trip inspection on a vehicle fitted with air brakes — checking the system for leaks, confirming it builds and holds pressure, testing the low-pressure warning and the spring brakes, and checking brake adjustment. Most candidates complete an air brake training course to prepare for it.

Knowledge first, then practical

Use this practice test to master the theory. The hands-on skills — draining reservoirs, running the leak-down test and measuring pushrod travel — are learned and assessed on a real vehicle as part of the practical component.

How do you book and take the air brake test?

Study the air brake section of the Driving Commercial Vehicles guide, then visit an ICBC driver licensing office to take the knowledge test.

  1. Study the air brake material in ICBC's Driving Commercial Vehicles guide and practise with this test.
  2. Go to a driver licensing office and apply to take the air brake knowledge test.
  3. Pay the knowledge test fee and complete the 25-question test, scoring at least 20 to pass.
  4. Take an air brake training course to learn the hands-on inspection skills.
  5. Pass the practical air brake test, which includes an air brake pre-trip inspection.
  6. Once both parts are complete, the Code 15 endorsement is added to your driver's licence.

After you pass

When you have passed both the knowledge test and the practical air brake test, the Code 15 air brake endorsement is added to your licence and you may operate a vehicle equipped with air brakes.

Frequently asked questions

How many questions are on the ICBC air brake knowledge test?
The air brake knowledge test has 25 multiple-choice questions. You need 20 correct — 80% — to pass, and you have 45 minutes to complete it. This practice test uses the same format.
Who needs an air brake endorsement in BC?
You need the Code 15 air brake endorsement to drive any vehicle equipped with an air brake system. That includes most large trucks and buses — many Class 1, 2 and 3 vehicles — and some larger recreational vehicles.
Is the air brake test only a written knowledge test?
No. The air brake endorsement requires both a written knowledge test and a practical air brake test. The practical test involves carrying out an air brake pre-trip inspection on a real vehicle. This practice test prepares you for the written knowledge component.
Can I take the air brake knowledge test in another language?
No. Unlike the car and motorcycle knowledge tests, the ICBC air brake knowledge test is offered in English only, and translators are not permitted during the test.
What happens if I fail the air brake knowledge test?
If you do not pass, you must wait seven days before trying again. After three failed attempts you must retake the air brake training course before you can test again, so it is worth preparing thoroughly first.
Which manual should I study for the air brake test?
Study the air brake section of ICBC's Driving Commercial Vehicles guide. It is the single guide that covers the air brake endorsement as well as the Class 1 to 4 commercial licences.