Why it is separate from the licence class
The Official MTO Air Brake Handbook: "In Ontario, most large commercial vehicles are equipped with an air brake system. You must have an air brake endorsement on your driver’s licence to drive these vehicles." The endorsement is about the brake system, not the vehicle size, so it attaches to any class: a Class D truck with air brakes needs a DZ, a straight truck with hydraulic brakes does not. A full Class A must have it to be any use, because the full Class A road test vehicle needs "a full air brake system on both the truck/tractor and trailer"; the restricted Class A does not, because its trailer has no air brakes. Air-over-hydraulic systems count as air brakes for the endorsement.
Ontario: the two routes to a Z
Route 1: a course and a referral envelope
You can take an air brake endorsement course from "a vehicle fleet owner, a community college, a safety organization". Who may use which: "If you have a Class A (Z) licence that you want to upgrade, you can take the course through any of the three options. If you have a B, C, D, E, F or G licence, you need to take the course with a vehicle fleet owner." At the end "you will receive a referral envelope. Take the envelope to a DriveTest centre within 6 months to get your air brake endorsement."
Route 2: the DriveTest knowledge and practical tests
Study the Official Air Brake Handbook (online, or a printed copy from DriveTest, ServiceOntario and retailers), then "take an air brake knowledge test at a DriveTest centre". After passing, book a practical test with your Ontario licence number, a first, second and third choice of location and a preferred date; cancel at least 48 hours ahead to avoid losing the fee. Fees for both tests are on the ministry’s fee list. The practical test is a demonstration of the daily air brake inspection: the checks on the compressor, governor, warning devices, leakage, brake adjustment and the parking and emergency brake, in the order the handbook teaches.
The handbook also notes that since 1 September 2023 an online air brake learning module replaces the air brake knowledge test at licence renewal, so the test in this section is for getting the endorsement, not keeping it.
What the knowledge test covers
The handbook’s chapters, and so the questions: how air brakes work (compressor, reservoirs, governor cut-in and cut-out), the dual-circuit system, the foundation brakes and slack adjusters, the spring parking and emergency brakes, trailer brakes and the tractor protection valve, ABS, the warning devices and the leakage tests, and the daily inspection. The Z air brake practice test on this site has 45 questions written from the handbook with an explanation for each; the AZ practice test covers the rest of the Class A knowledge test.
Alberta: the Q endorsement
Alberta’s Class 1 Learning Pathway builds the air brake course into the licence route: "An additional 8-hour air brake training course is required if a learner does not already have a Q endorsement on their licence", taken during the Core Learning tier before the road test. Drivers of air-braked vehicles in other classes take the same course with a licensed school. The full pathway is on the MELT across Canada page.
Other provinces
Saskatchewan’s Class 1 page states the licence "does not permit the licence holder to operate vehicles with air brakes, motorcycles or school buses without an appropriate endorsement", so the Q endorsement is added through SGI’s air brake course and test. British Columbia (ICBC), Manitoba (MPI), Quebec (SAAQ) and the Atlantic provinces each run an equivalent air brake endorsement with their own course, test and fee; the principle is the same everywhere, only the letter and the booking route change. A driver who moves provinces keeps the endorsement when exchanging the licence, as Ontario’s page says of licence classes generally: "your Ontario licence will be the same class."
Worked example
Example. A Class G driver in Ontario is hired to drive a 12,000 kg straight truck with air brakes. She needs a Class D (knowledge test, medical, road test in a Class D vehicle) and a Z. Holding only a G, her course option is a vehicle fleet owner’s course, so the employer’s in-house course and referral envelope is the natural route; otherwise she studies the handbook and takes the knowledge and practical tests at DriveTest. She leaves with a DZ. If she later goes for an AZ, the Z carries over and only the Class A steps remain.
Common mistakes
- Letting the referral envelope pass its six months.
- Taking a college or safety-organisation course on a G licence, which does not qualify; on a G the course must be a fleet owner’s.
- Booking the practical test before passing the knowledge test.
- Assuming a Class A licence includes air brakes. Without the Z it does not.
- Skipping the daily inspection practice; the practical test is the inspection.