Ontario Air Brake Test Questions and Answers – Printable

100 Ontario air brake (Z) practice questions on one printable page with a separate answer key. Print it or save it as a PDF from your browser.

No sign-up
Every answer explained
Independent · not a government site

100 questions
Answer key included
Free, no sign-up

This page puts 100 air brake questions from our Ontario bank on one sheet, with the answers on a separate key at the end so you can test yourself on paper. Use your browser's print command and choose Save as PDF if you want a file to study offline or on the bus.

The questions are spread across every chapter of the Official Air Brake Handbook: the air supply system, service, spring and trailer brakes, foundation brakes, brake adjustment and the functional tests you do on the practical exam. For explanations of each answer, take the same topics as interactive practice tests on this site.

Jump to the answer key

1.When must wheel chocks be used during an air brake inspection?
1. Only if the truck is carrying a load
2. Only during the governor cut-out test
3. When you leave the seat with brakes off
4. Only when parked on gravel surfaces
2.Where is an air dryer located?
1. Between the compressor and the supply tank
2. Between the foot valve and brake chambers
3. Inside the secondary tank
4. On the trailer supply line
3.You find small holes on a brake chamber that were made by the manufacturer. What are they?
1. Corrosion that must be reported
2. Normal vent holes, not a defect
3. Impact damage needing repair
4. Signs the chamber was caged
4.What does a pushrod stroke indicator show?
1. The date of the last brake inspection
2. Stroke is past the limit
3. How much brake lining is left
4. The chamber's current air pressure
5.On a wedge brake, which way do the brake chamber pushrods point?
1. Outward, away from the wheel
2. Forward along the slack adjuster
3. Up toward the frame rail
4. Inward, toward the shoes and drum
6.How much notice must you give to cancel a practical test without a fee?
1. No notice is needed
2. At least 7 days
3. At least 48 hours
4. At least 2 hours
7.What is the usual colour code for trailer air couplers?
1. Red for service, black for supply
2. Yellow for supply, green for service
3. Blue for supply, red for service
4. Red for supply, blue for service
8.What moves inside the service chamber when air enters it?
1. A wedge between the shoes
2. A one-way check valve
3. A flexible rubber diaphragm
4. A large coil spring
9.In Ontario, do you need a Z endorsement to drive a truck with air-over-hydraulic brakes?
1. No, only full air brakes need it
2. Yes, it is required
3. Only if the truck is over 11,000 kg
4. Only when towing a trailer
10.How often does Ontario law require air brake adjustment to be checked?
1. Once a week
2. Only at the annual inspection
3. At least once each day
4. Once a month
11.How do you lower air pressure for the low-air warning test?
1. Pull out the trailer supply valve
2. Open the supply tank drain valve
3. Disconnect the trailer service gladhand
4. Press and release the pedal repeatedly
12.Why might spring brakes fail to hold a parked truck on a hill?
1. The governor cut-in is set too high
2. The air dryer is purging too often
3. The brakes are out of adjustment
4. The trailer supply valve is closed
13.By law, what must a driver do on finding an air brake defect?
1. Report it to the vehicle operator
2. Ignore it if the truck still stops
3. Report it only after a collision
4. Fix it before the next shift
14.How far above cut-in pressure is cut-out pressure normally set?
1. 5 to 10 psi higher
2. 40 to 50 psi higher
3. 60 to 70 psi higher
4. 20 to 25 psi higher
15.On a steering axle, which slack adjuster condition is a defect?
1. Same length but different brand names
2. Unequal effective lengths
3. Different paint colours on each side
4. Both pushrods attached in the same hole
16.Using Method 2, how do you get the applied stroke?
1. Divide the applied reading by two
2. Add the two readings together
3. Use only the released reading
4. Measurement 2 minus measurement 1
17.Which parts are found on every air disc brake?
1. Wedges and rollers
2. Camshafts and anchor pins
3. Drums and spiders
4. Calipers and rotors
18.Which book is the official study guide for the air brake knowledge test?
1. The Official Bus Handbook
2. The Official MTO Driver's Handbook
3. The Official Air Brake Handbook
4. The CVOR Safety Manual
19.How do you supply air to a trailer with the trailer supply valve?
1. Hold it for five seconds
2. Push the knob in
3. Turn it to the left
4. Pull the knob out
20.What is pushrod stroke?
1. How long the compressor takes to cut out
2. How far the shoes travel on release
3. Distance the pushrod moves out
4. How far the pedal moves when pressed
21.Before you measure anything on a brake assembly, how should it feel?
1. Hot, right after a hard stop
2. Warm, so parts are expanded
3. Damp, after draining the tanks
4. Cool to the touch
22.You double both your load and your speed. How does stopping distance change?
1. It becomes about four times longer
2. It becomes about six times longer
3. It stays roughly the same
4. It becomes about eight times longer
23.To test the low-air warning, what pressure should you start above?
1. 145 psi (1000 kPa)
2. 60 psi (414 kPa)
3. 90 psi (621 kPa)
4. 55 psi (380 kPa)
24.Air pressure drops below about 60 psi while driving. What does the control valve do?
1. Locks the spring brakes in the released position
2. Exhausts air so spring brakes apply
3. Opens the supply tank safety valve
4. Switches over to using the trailer's air
25.Where should you park to inspect your air brakes?
1. Away from traffic and other hazards
2. Beside the fuel pumps
3. In the right lane with flashers on
4. On a slight downhill slope
26.When does an air dryer expel the moisture it has collected?
1. When the compressor reaches cut-out
2. Each time the pedal is released
3. Only when the engine is shut off
4. When the low-air warning activates
27.How should a compressor drive belt feel under firm hand pressure?
1. It should not move at all
2. It should give slightly
3. It should move several inches
4. It should slip off the pulley
28.Is it legal to drive with one brake out of adjustment if the others are fine?
1. Yes, until the next annual
2. Yes, on the trailer only
3. No, it is prohibited
4. Yes, below 80 km/h
29.How is a wedge brake applied?
1. Pads clamp both faces of a spinning rotor
2. A camshaft turns between two steel rollers
3. A strong spring pulls the shoes inward
4. The pushrod drives a wedge between shoes
30.What are the two ways to earn a Z endorsement in Ontario?
1. An approved course, or DriveTest tests
2. A mechanic's licence, or a fee
3. An online video, or a road test
4. A medical report, or a trainer's letter
31.What does the trailer hand valve do?
1. Applies only the trailer service brakes
2. Releases the tractor's spring brakes
3. Closes the tractor protection valve
4. Fills the trailer air tanks quickly
32.What are the brakes used for normal stopping called?
1. Spring brakes
2. Emergency brakes
3. Parking brakes
4. Service brakes
33.What makes sure air moves through an air brake system as fast as possible?
1. Larger brake drums at each wheel
2. Heavier return springs in each shoe
3. Special valves in the system
4. A second, faster compressor
34.When does a vehicle have its full braking ability?
1. When every brake is in adjustment
2. Whenever the tanks are above 100 psi
3. Whenever the ABS warning light is off
4. Whenever the spring brakes are released
35.During the low-air warning test, what must the ignition be?
1. Off, with the engine stopped
2. Off, with the battery disconnected
3. On; the engine may run or be off
4. On, with the engine at 1,200 rpm
36.How do you release DD3 parking brakes?
1. Push the blue knob, then start the engine
2. Pull the valve, then pump the pedal twice
3. Turn the caging bolt one full turn out
4. Operate the valve, then hold the pedal 3–5 s
37.A truck does not comply with the Highway Traffic Act. Who must keep it off the road?
1. The driver, operator and owner
2. Only the mechanic who inspected it
3. Only the vehicle owner
4. Only the police officer
38.What part makes the compressor stop and start pumping air at set pressures?
1. The safety valve
2. The governor
3. The foot valve
4. The check valve
39.When should you inspect the air compressor?
1. With the engine stopped
2. While draining the tanks
3. While the governor is cutting in
4. With the engine at high idle
40.Before measuring pushrod stroke, what must air pressure be?
1. At zero, all tanks drained
2. Below 60 psi, spring brakes applied
3. Above 90 psi, spring brakes released
4. Exactly 120 psi, engine running
41.What part serves as the main mounting base for the brake shoes in an S-cam brake?
1. The clevis pin
2. The brake spider
3. The slack adjuster
4. The dust shield
42.Who can offer an air brake endorsement course?
1. Only ServiceOntario offices
2. Only truck and trailer dealerships
3. Only DriveTest centres
4. Fleet owners, colleges, safety groups
43.Can the trailer hand valve be used to hold a parked combination?
1. No, never for parking or emergencies
2. Yes, but only for short stops
3. Yes, as long as the engine stays running
4. Only when parked on level ground
44.Can you rely on hose colours to identify air lines on every vehicle?
1. Yes, but only on trailers
2. No, older vehicles may not follow the code
3. Yes, all vehicles use one colour code
4. No, colours are never used
45.Why do hydraulic brakes act at the wheels almost instantly?
1. Brake fluid cannot be compressed
2. Fluid is stored under 145 psi
3. The lines are shorter than air lines
4. They use a stronger return spring
46.Should you expect ABS to shorten your stopping distance?
1. Yes, by about half the distance
2. Yes, when the trailer also has ABS
3. No, it prevents lock, not distance
4. Yes, but only on dry pavement
47.The warning came on at 62 psi and went off at 68 psi as pressure rose. Is that a defect?
1. Yes, it must go off at 55 psi
2. Yes, it must come on at 80 psi
3. No, on and off points can differ
4. Yes, they must be identical
48.Some tractors have a round blue knob. What does it control?
1. The front wheel-limiting valve
2. The trailer supply line
3. The air dryer purge
4. The tractor's spring brakes only
49.Why should the engine be off for most air brake inspections?
1. The compressor overheats if running
2. The gauges only work with it off
3. Air pressure is higher with it off
4. Moving engine parts are a hazard
50.What is the highest actual cut-out pressure allowed?
1. 120 psi (828 kPa)
2. 145 psi (1000 kPa)
3. 175 psi (1207 kPa)
4. 150 psi (1035 kPa)
51.An air line was repaired with a fitting not approved for air brakes. What is it?
1. Acceptable for one trip only
2. Acceptable if it does not leak
3. Acceptable on trailer lines only
4. A defect; it is not allowed
52.What is the adjustment limit for a type 30 long-stroke chamber with square ports?
1. 3 in. (76 mm)
2. 2-1/2 in. (64 mm)
3. 2-1/4 in. (57 mm)
4. 2 in. (51 mm)
53.Which feature of S-cam brakes makes it easy to check brake adjustment?
1. The exposed pushrod
2. The hidden brake spider
3. The self-adjusting wedge
4. The sealed dust shield
54.Which item is optional for the air brake practical test?
1. Wheel chocks or blocks for the wheels
2. A chart of brake adjustment limits
3. A way to hold the brake pedal down
4. A watch with a second hand for timing
55.What is the risk with a spring brake priority trailer?
1. It needs its own separate air compressor
2. Its spring brakes can never be released
3. It cannot be used in a double combination
4. It can roll before service air is ready
56.Where is compressed air turned into the mechanical force that applies a brake?
1. In the governor on the compressor
2. In the brake chamber at the wheel
3. In the supply (wet) tank
4. In the foot valve under the pedal
57.Why can a badly overheated brake drum stop touching the brake shoe?
1. The pushrod retracts when it gets hot
2. Air pressure falls sharply in hot weather
3. The hot drum expands away from the shoe
4. The shoe shrinks as it cools down
58.What do engine brakes and retarders help you avoid?
1. Pushrod measurement
2. Compressor cut-in
3. Low tire pressure
4. Excessive brake temperature
59.What is the recommended way to test automatic trailer spring brake application?
1. Pull out the trailer supply valve
2. Disconnect the line under pressure
3. Pull the trailer hand valve
4. Pump the pedal to zero air
60.What should a driver know about the spring brake control on a vehicle they have not driven before?
1. Which type it is and how it works
2. Only where the drain valve is
3. Nothing; all valves work the same
4. Only the colour of the knob
61.Before a test that releases the parking brakes, what keeps the vehicle from rolling?
1. The trailer hand valve
2. The low-air warning
3. The tractor protection valve
4. Wheel chocks or blocks
62.What does an alcohol evaporator do?
1. Helps stop moisture from freezing
2. Cleans oil off the brake linings
3. Cools the compressor on hot days
4. Lubricates the slack adjusters daily
63.What does a slack adjuster do?
1. Measures the pushrod stroke for you
2. Controls when the compressor cuts in
3. Drains moisture from the brake chamber
4. Acts as a lever on the camshaft
64.What is usually the easiest way to learn your vehicle's brake chamber sizes?
1. Count the bolts on the clamp ring
2. Measure the length of the pushrod
3. Your employer or the owner's manual
4. Weigh each chamber on a scale
65.Which three types of foundation brakes does the Ontario air brake handbook describe?
1. Disc, cone and wedge
2. S-cam, band and spring
3. S-cam, disc and wedge
4. Drum, band and cone
66.From what age must the learning module and practical test be done every year?
1. 70
2. 65
3. 80
4. 75
67.What controls the tractor protection valve?
1. The foot valve only
2. The governor
3. The spring brake control valve
4. The trailer supply valve
68.What type of brake chamber do almost all commercial vehicles use?
1. Welded-shell chambers
2. Hydraulic wheel cylinders
3. Clamp-type chambers
4. Bolt-flange chambers
69.What do air brake systems use to produce the force that applies the brakes?
1. Brake fluid in a master cylinder
2. Electric motors at each wheel
3. Compressed air stored in tanks
4. Vacuum from the engine intake
70.What is brake fade?
1. The delay as air travels to the wheels
2. Weaker brakes as they heat up
3. A slow leak from the supply tank
4. Wear marks on the inside of the drum
71.How do you find the governor's cut-out pressure?
1. Note where the warning light comes on
2. Note where the safety valve opens
3. Note where the gauges stop climbing
4. Note where the spring brakes apply
72.Before driving, what should you confirm about air pressure and the spring brakes?
1. Pressure is below 60 psi to save fuel
2. The service section is empty of air
3. The springs are caged for the whole trip
4. There is enough pressure to keep them off
73.What is the most common reason commercial vehicles are taken out of service?
1. Expired licence plates
2. Dirty windshields
3. Low fuel
4. Air brakes out of adjustment
74.Why are there primary and secondary air tanks and circuits?
1. So one circuit can stop you if one fails
2. To double the air pressure available
3. To feed the trailer and tractor separately
4. So the compressor can rest between stops
75.You apply the brakes and see a lining that does not touch the drum. What does it show?
1. A brake with new linings
2. A normal cold brake
3. A malfunctioning brake
4. A properly adjusted brake
76.What is the most reliable way to inspect brake adjustment?
1. Listen for air when braking
2. Measure the applied pushrod stroke
3. Check the drum temperature
4. Feel how far the pedal travels
77.What is the most common foundation brake on air-braked commercial vehicles?
1. The S-cam drum brake
2. The band brake
3. The wedge brake
4. The air disc brake
78.After the course you get a referral envelope. How long do you have to take it to DriveTest?
1. 6 months
2. 2 years
3. 30 days
4. 1 year
79.How are two gladhands joined?
1. Screwed together clockwise by hand
2. Seals together at an angle, then rotated
3. Pushed straight together until they click
4. Clamped together with a metal hose clip
80.Why must brake linkage be readjusted at regular intervals?
1. Diaphragms shrink in cold weather
2. Air tanks lose capacity over time
3. Governor settings drift each week
4. Wear makes the stroke longer
81.A disc brake on an air-braked truck uses which parts at the wheel?
1. A rotor and a caliper with pads
2. A drum and two curved shoes
3. A wedge and two brake shoes
4. A spider and an S-shaped cam
82.Where is the ABS warning lamp for a trailer usually mounted?
1. Inside the trailer near the kingpin
2. Under the trailer's rear bumper
3. On the trailer's landing gear
4. Where you can see it in the mirror
83.How do you test that the spring brakes can hold the vehicle?
1. Pump the pedal while they are applied
2. Apply them while at highway speed
3. Apply them, then pull gently in low gear
4. Release them and coast down a hill
84.Spring brakes are designed for which two jobs?
1. Normal stops and slowing on hills
2. Anti-lock control and steering
3. Trailer coupling and uncoupling
4. Parking and emergency stopping
85.Which safety equipment may be needed while inspecting air brakes?
1. A high-visibility vest only
2. A respirator and ear plugs only
3. Rubber gloves and an apron only
4. Safety glasses, steel toes, bump cap
86.Why should you stay out of the path of air exhausting from brake valves?
1. Its debris can hurt eyes and ears
2. It is cold enough to cause frostbite
3. It contains alcohol vapour that can ignite
4. It can reverse the one-way check valves
87.How should you check a brake chamber for leaks?
1. With only the spring brakes applied
2. With the chamber removed from the axle
3. With the engine off and no air at all
4. Spring brakes off, service brakes on
88.Your steer axle uses standard type 24 chambers. Which stroke limit applies to them?
1. 1-3/4 in. (45 mm)
2. 2 in. (51 mm)
3. 1-3/8 in. (35 mm)
4. 2-1/4 in. (57 mm)
89.Why can the inner parts of an S-cam brake be hard to inspect?
1. They are sealed inside the supply air tank
2. Shields or backing plates hide them
3. They sit inside the service brake chamber
4. They are covered by the slack adjuster arm
90.Since September 1, 2023, what replaces the air brake knowledge test at renewal?
1. An online air brake learning module
2. A medical exam
3. A video quiz at ServiceOntario
4. A second practical test
91.What does the trailer supply valve knob normally look like?
1. Blue and round
2. Red and eight-sided
3. Yellow and four-sided
4. Black and triangular
92.How does Ontario law treat a brake whose stroke is past the adjustment limit?
1. As a minor issue to note weekly
2. As acceptable on trailer axles
3. As normal wear until the next annual
4. As a defect needing prompt attention
93.When brakes slow a moving truck, what is the vehicle's energy of motion turned into?
1. Electricity
2. Heat
3. Compressed air
4. Brake fluid pressure
94.As speed or weight goes up, how must you use the brake pedal to get the same stop?
1. Use the trailer hand valve instead
2. Press it more lightly than usual
3. Press it further
4. Pump it rapidly several times
95.While draining tanks, you see a lot of water from the secondary tank. What should you do?
1. Add more alcohol to the evaporator
2. Drain the supply tank last
3. Nothing; it is always wet
4. Report it; that is not normal
96.What does it mean to cage a spring brake?
1. Lock the spring brake fully applied
2. Drain all the air from the spring section
3. Compress the spring so it can't apply
4. Replace the diaphragm with a new one
97.When is it safe to get under a vehicle during an inspection?
1. Only if spring brakes or blocks hold it
2. Only after the trailer has been uncoupled
3. Whenever the engine has been shut off
4. Whenever air pressure is above 90 psi
98.What is the cut-in pressure?
1. Where the safety valve opens to vent air
2. Where the spring brakes begin to apply
3. Where the low-air warning device comes on
4. Where the compressor resumes pumping
99.What does a driver's air brake component inspection mainly involve?
1. Measuring each drum's inside diameter
2. Removing wheels to see the shoes
3. Looking at visible parts
4. Taking the brake chambers apart
100.How much can adjustment limits differ between standard and long-stroke chambers?
1. By about 1 mm
2. By about 5 mm
3. By 19 mm or more
4. They never differ

Answer key with explanations

1. C — When you leave the seat with brakes off
Chocks or blocks must be used whenever a test requires the driver to leave the seat with the parking brakes released.
Compliance and safe inspection · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 8 Air Brake Compliance, Air Brake Compliance — Safety concerns
2. A — Between the compressor and the supply tank
The air dryer sits between the compressor and the supply tank, removing moisture before the air reaches the tank.
Air supply subsystem · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 2 Air Supply Subsystem, Air Supply Subsystem — Air dryer
3. B — Normal vent holes, not a defect
Manufactured vent holes are not a concern. Holes or cracks caused by impact or other damage make the chamber defective.
Inspecting brake components · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 9 Inspecting Air Brake Components, Inspecting Air Brake Components — Inspecting air brake chambers
4. B — Stroke is past the limit
Pushrods are often marked with an indicator that becomes visible when stroke exceeds the limit. They must be properly installed and drivers trained to use them.
Brake adjustment and pushrod stroke · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 11 Inspecting Air Brake Adjustment, Inspecting Air Brake Adjustment — Brake stroke indicators
5. D — Inward, toward the shoes and drum
Wedge brake chambers are mounted so their pushrods face inward toward the shoes and drum, which is why there is no exposed linkage.
Foundation brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 6 Foundation Brakes, Foundation Brakes — Wedge brakes
6. C — At least 48 hours
Cancel at least 48 hours before the appointment to avoid a cancellation fee.
Getting and renewing the Z endorsement · Based on: ontario.ca — Get a truck driver's licence (updated Sept. 2026), Air brake (Z) endorsement program, Air brake (Z) endorsement program — Book a practical test
7. D — Red for supply, blue for service
Couplers are usually colour-coded during manufacture: red for the supply (emergency) line and blue for the service line.
Trailer brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 5 Trailer Brake Subsystem, Trailer Brake Subsystem — Connecting a trailer
8. C — A flexible rubber diaphragm
Compressed air fills the chamber and moves the diaphragm, which pushes the pushrod out to apply the brake.
Service brakes and brake chambers · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 3 Service Brake Subsystem, Service Brake Subsystem — Air brake chambers
9. B — Yes, it is required
Air-over-hydraulic systems combine compressed air with hydraulic brakes, and Ontario requires a Z endorsement to drive them.
How vehicle brakes work · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 1 Vehicle Braking Systems, Vehicle Braking Systems — Other braking systems
10. C — At least once each day
The Highway Traffic Act and regulations require vehicles with air brakes to be checked at least once a day for correct adjustment.
Speed, weight, heat and ABS · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 7 Demands on Brakes While Driving, Demands on Brakes While Driving — Brakes must be adjusted correctly
11. D — Press and release the pedal repeatedly
Reduce pressure by repeatedly pressing and releasing the brake pedal while watching the gauges.
Air brake system tests · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 10 Inspecting Air Brake System Operation, Inspecting Air Brake System Operation — Testing low air-pressure warning devices
12. C — The brakes are out of adjustment
Spring brakes work only as well as the brakes are adjusted. Poor adjustment reduces their ability to stop or hold the vehicle, as it does for service brakes.
Spring (parking and emergency) brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 4 Spring (Parking and Emergency) Brake Subsystem, Spring Brake Subsystem — Spring brake control valves
13. A — Report it to the vehicle operator
Drivers are required by law to report any defects of the air brake system to the vehicle operator.
Compliance and safe inspection · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 8 Air Brake Compliance, Air Brake Compliance — Key points
14. D — 20 to 25 psi higher
Cut-out is normally 138 to 173 kPa (20 to 25 psi) above cut-in. Together they define the normal operating range.
Air supply subsystem · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 2 Air Supply Subsystem, Air Supply Subsystem — Normal pressure range
15. B — Unequal effective lengths
Mismatched slack adjuster effective length on a steering axle is a defect, because it unbalances braking. Some models look different but must still have equal effective length.
Inspecting brake components · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 9 Inspecting Air Brake Components, Inspecting Air Brake Components — Inspecting air brake chambers
16. D — Measurement 2 minus measurement 1
Measure from a point on the pushrod to a fixed point with brakes released (measurement 1), then applied (measurement 2), and subtract 1 from 2.
Brake adjustment and pushrod stroke · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 11 Inspecting Air Brake Adjustment, Inspecting Air Brake Adjustment — Measuring applied pushrod stroke
17. D — Calipers and rotors
All disc air brakes use calipers and rotors, along with pads, brake chambers and often slack adjusters.
Foundation brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 6 Foundation Brakes, Foundation Brakes — Disc brakes
18. C — The Official Air Brake Handbook
Ontario's Official Air Brake Handbook prepares you for the knowledge test. It is free online or can be bought in print.
Getting and renewing the Z endorsement · Based on: ontario.ca — Get a truck driver's licence (updated Sept. 2026), Air brake (Z) endorsement program, Air brake (Z) endorsement program — Official Air Brake Handbook
19. B — Push the knob in
Push the red knob in to open the valve and supply air to the trailer; pull it out to close it or when no trailer is attached.
Trailer brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 5 Trailer Brake Subsystem, Trailer Brake Subsystem — Trailer air supply valve
20. C — Distance the pushrod moves out
Stroke length is the distance the pushrod travels out of the brake chamber when the brakes are applied.
Service brakes and brake chambers · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 3 Service Brake Subsystem, Service Brake Subsystem — Air brake chambers
21. D — Cool to the touch
The handbook says to make sure the brake assembly is cool to the touch before attempting brake measurements. Hot parts are expanded and can burn you.
How vehicle brakes work · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 1 Vehicle Braking Systems, Vehicle Braking Systems — Stopping a vehicle
22. D — It becomes about eight times longer
Doubling weight doubles the distance and doubling speed multiplies it by four, so together it is about eight times longer.
Speed, weight, heat and ABS · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 7 Demands on Brakes While Driving, Demands on Brakes While Driving — Vehicle speed and weight
23. C — 90 psi (621 kPa)
Begin with pressure above 621 kPa (90 psi). If pressure is too low, the warning comes on as soon as the key is turned on.
Air brake system tests · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 10 Inspecting Air Brake System Operation, Inspecting Air Brake System Operation — Testing low air-pressure warning devices
24. B — Exhausts air so spring brakes apply
The valve responds to low system pressure by exhausting the remaining air holding the springs off. The knob pops out and the spring brakes apply suddenly, causing an uncontrolled stop.
Spring (parking and emergency) brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 4 Spring (Parking and Emergency) Brake Subsystem, Spring Brake Subsystem — Spring brake control valves
25. A — Away from traffic and other hazards
Park away from traffic and other hazards to give yourself a safe work area around the vehicle.
Compliance and safe inspection · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 8 Air Brake Compliance, Air Brake Compliance — Safety concerns
26. A — When the compressor reaches cut-out
Collected moisture is blown out with high-pressure air when the compressor reaches cut-out. That purge sound is also a sign cut-out has been reached.
Air supply subsystem · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 2 Air Supply Subsystem, Air Supply Subsystem — Air dryer
27. B — It should give slightly
The belt should give slightly when firmly pressed. Excessive movement means it is too loose. A loose, cut or frayed belt is defective.
Inspecting brake components · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 9 Inspecting Air Brake Components, Inspecting Air Brake Components — Inspecting air compressors
28. C — No, it is prohibited
The Highway Traffic Act and regulations prohibit operating a vehicle with a brake that is out of adjustment.
Brake adjustment and pushrod stroke · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 11 Inspecting Air Brake Adjustment, Inspecting Air Brake Adjustment — Key points
29. D — The pushrod drives a wedge between shoes
In a wedge brake, the chamber pushrod slides a wedge between the shoes, forcing them outward against the drum.
Foundation brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 6 Foundation Brakes, Foundation Brakes — Wedge brakes
30. A — An approved course, or DriveTest tests
You can attend an air brake endorsement course, or take the knowledge and practical tests at a DriveTest centre.
Getting and renewing the Z endorsement · Based on: ontario.ca — Get a truck driver's licence (updated Sept. 2026), Air brake (Z) endorsement program, Air brake (Z) endorsement program — Who needs it
31. A — Applies only the trailer service brakes
A hand valve on the steering column or dash lets the driver apply the trailer service brakes independently of the towing vehicle's brakes.
Trailer brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 5 Trailer Brake Subsystem, Trailer Brake Subsystem — Applying trailer service brakes
32. D — Service brakes
Air-braked vehicles have separate systems for normal stopping and for parking and emergency use. The ones used for normal stops are the service brakes.
Service brakes and brake chambers · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 3 Service Brake Subsystem, Service Brake Subsystem — Introduction
33. C — Special valves in the system
Special valves help air reach and leave the brakes quickly, which keeps the unavoidable delay to a split second.
How vehicle brakes work · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 1 Vehicle Braking Systems, Vehicle Braking Systems — Air brakes differ from hydraulic brakes
34. A — When every brake is in adjustment
Vehicles have full braking ability only when all brakes are properly adjusted, with each pushrod stroke within its limit.
Speed, weight, heat and ABS · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 7 Demands on Brakes While Driving, Demands on Brakes While Driving — Brakes must be adjusted correctly
35. C — On; the engine may run or be off
The engine may be stopped or running, but the ignition must be on or the warning will not activate.
Air brake system tests · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 10 Inspecting Air Brake System Operation, Inspecting Air Brake System Operation — Testing low air-pressure warning devices
36. D — Operate the valve, then hold the pedal 3–5 s
Releasing DD3 brakes requires operating the control valve and then pressing the brake pedal for three to five seconds.
Spring (parking and emergency) brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 4 Spring (Parking and Emergency) Brake Subsystem, Spring Brake Subsystem — DD3 brake chamber
37. A — The driver, operator and owner
When a vehicle fails to comply, the driver, operator and owner must all ensure it is not driven on any road or highway.
Compliance and safe inspection · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 8 Air Brake Compliance, Air Brake Compliance — Safety standards for commercial vehicles
38. B — The governor
The compressor turns whenever the engine runs, so the governor controls when it pumps: it stops it at cut-out and restarts it at cut-in.
Air supply subsystem · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 2 Air Supply Subsystem, Air Supply Subsystem — Governor
39. A — With the engine stopped
Air compressors must always be inspected with the engine stopped, checking mountings, brackets, pulleys and belt.
Inspecting brake components · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 9 Inspecting Air Brake Components, Inspecting Air Brake Components — Inspecting air compressors
40. C — Above 90 psi, spring brakes released
Secure the vehicle with chocks, make sure pressure is above 621 kPa (90 psi) and release the spring brakes.
Brake adjustment and pushrod stroke · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 11 Inspecting Air Brake Adjustment, Inspecting Air Brake Adjustment — Measuring applied pushrod stroke
41. B — The brake spider
The brake spider is the main mounting base for the shoes. Anchor pins attach one end of each shoe to it.
Foundation brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 6 Foundation Brakes, Foundation Brakes — "S" cam brakes
42. D — Fleet owners, colleges, safety groups
Courses are offered by vehicle fleet owners, community colleges and safety organizations.
Getting and renewing the Z endorsement · Based on: ontario.ca — Get a truck driver's licence (updated Sept. 2026), Air brake (Z) endorsement program, Air brake (Z) endorsement program — Air brake endorsement course
43. A — No, never for parking or emergencies
Trailer hand valves must never be used for parking or emergency stops; air can leak away and release the brakes.
Trailer brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 5 Trailer Brake Subsystem, Trailer Brake Subsystem — Applying trailer service brakes
44. B — No, older vehicles may not follow the code
Manufacturers currently follow an industry colour code for hoses and tubes, but older vehicles may not.
Service brakes and brake chambers · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 3 Service Brake Subsystem, Service Brake Subsystem — Brake hoses and tubes
45. A — Brake fluid cannot be compressed
Because brake fluid does not compress, pedal force is passed straight to each wheel. Air must flow through the system first, which causes a short delay.
How vehicle brakes work · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 1 Vehicle Braking Systems, Vehicle Braking Systems — Air brakes differ from hydraulic brakes
46. C — No, it prevents lock, not distance
ABS helps prevent wheel lock but you should not expect it to shorten stopping distance. On clean dry roads you will notice no difference.
Speed, weight, heat and ABS · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 7 Demands on Brakes While Driving, Demands on Brakes While Driving — Anti-lock braking systems
47. C — No, on and off points can differ
The pressure at which the device deactivates on a rise is not necessarily the same as where it activates on a drop. 62 psi is above the 55 psi minimum.
Air brake system tests · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 10 Inspecting Air Brake System Operation, Inspecting Air Brake System Operation — Testing low air-pressure warning devices
48. D — The tractor's spring brakes only
An optional tractor parking-brake valve, normally with a round blue knob, releases the tractor spring brakes while the trailer spring brakes stay applied.
Spring (parking and emergency) brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 4 Spring (Parking and Emergency) Brake Subsystem, Spring Brake Subsystem — Spring brake control valves
49. D — Moving engine parts are a hazard
Moving parts in the engine compartment pose hazards, so inspections should be done with the engine stopped unless a test needs it running.
Compliance and safe inspection · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 8 Air Brake Compliance, Air Brake Compliance — Safety concerns
50. B — 145 psi (1000 kPa)
Actual cut-out must never be higher than 1000 kPa (145 psi). 150 psi is where safety valves normally open.
Air supply subsystem · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 2 Air Supply Subsystem, Air Supply Subsystem — Normal pressure range
51. D — A defect; it is not allowed
Air brake systems require fittings designed and approved for that use. Improper fittings or repairs are prohibited and are a defect.
Inspecting brake components · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 9 Inspecting Air Brake Components, Inspecting Air Brake Components — Inspecting brake hoses and tubes
52. B — 2-1/2 in. (64 mm)
The type 30 LS (square ports, tag and cover marking) has an adjustment limit of 2-1/2 inches (64 mm).
Brake adjustment and pushrod stroke · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 11 Inspecting Air Brake Adjustment, Brake Adjustment Limits Chart — Clamp-type chambers
53. A — The exposed pushrod
S-cam brakes have an exposed pushrod and linkage, giving easy access for checking adjustment.
Foundation brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 6 Foundation Brakes, Foundation Brakes — "S" cam brakes
54. B — A chart of brake adjustment limits
The handbook lists a chart of brake adjustment limits as optional. The other items are required.
Getting and renewing the Z endorsement · Based on: ontario.ca — Get a truck driver's licence (updated Sept. 2026), Air brake (Z) endorsement program, Air brake (Z) endorsement program — What to bring
55. D — It can roll before service air is ready
Spring brake priority fills the spring brake tank first, so the trailer can be towed before its service brake tank has enough air to work.
Trailer brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 5 Trailer Brake Subsystem, Trailer Brake Subsystem — Spring brake or service brake priority
56. B — In the brake chamber at the wheel
Air brake chambers are round metal containers at each wheel where compressed air is converted into mechanical force.
Service brakes and brake chambers · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 3 Service Brake Subsystem, Service Brake Subsystem — Air brake chambers
57. C — The hot drum expands away from the shoe
Heat makes the drum expand, and it can grow far enough that the shoe no longer reaches it. That is one reason overheated brakes can fail.
How vehicle brakes work · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 1 Vehicle Braking Systems, Vehicle Braking Systems — Stopping a vehicle
58. D — Excessive brake temperature
Engine brakes, retarders and other auxiliary brakes slow the vehicle using engine compression, hydraulic or electric means, helping avoid excessive brake heat.
Speed, weight, heat and ABS · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 7 Demands on Brakes While Driving, Demands on Brakes While Driving — Brakes create heat
59. A — Pull out the trailer supply valve
With the trailer fully charged, close (pull out) the trailer supply valve; the trailer spring brakes should apply. Disconnecting the pressurized line also works but is not recommended.
Air brake system tests · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 10 Inspecting Air Brake System Operation, Inspecting Air Brake System Operation — Testing the automatic application of the trailer spring brakes
60. A — Which type it is and how it works
Some vehicles reverse the push/pull action or use a toggle valve, so drivers must be familiar with the control used in their vehicle.
Spring (parking and emergency) brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 4 Spring (Parking and Emergency) Brake Subsystem, Spring Brake Subsystem — Spring brake control valves
61. D — Wheel chocks or blocks
Secure the vehicle with wheel chocks or blocks to prevent movement during the inspection. The hand valve must never be used to hold a vehicle.
Compliance and safe inspection · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 8 Air Brake Compliance, Air Brake Compliance — Safety concerns
62. A — Helps stop moisture from freezing
It adds alcohol vapour that mixes with moisture or ice and reduces its tendency to freeze. Only products made for this purpose may be used.
Air supply subsystem · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 2 Air Supply Subsystem, Air Supply Subsystem — Alcohol evaporator
63. D — Acts as a lever on the camshaft
Slack adjusters are levers that multiply the force of the brake chambers; their effective length is critical.
Inspecting brake components · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 9 Inspecting Air Brake Components, Inspecting Air Brake Components — Inspecting air brake chambers
64. C — Your employer or the owner's manual
You are most likely to get chamber sizes from your employer or the owner's manual, avoiding the need to measure the clamp or find size markings.
Brake adjustment and pushrod stroke · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 11 Inspecting Air Brake Adjustment, Inspecting Air Brake Adjustment — Brake chamber size
65. C — S-cam, disc and wedge
The three foundation brake designs are S-cam brakes, disc brakes and wedge brakes. A vehicle can even use more than one type.
Foundation brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 6 Foundation Brakes, Foundation Brakes — Types of foundation brakes
66. C — 80
Once you reach 80, you need the online module and the practical test each year to renew the endorsement. Under 80, renewal is usually every five years.
Getting and renewing the Z endorsement · Based on: ontario.ca — Get a truck driver's licence (updated Sept. 2026), Air brake (Z) endorsement program, Air brake (Z) endorsement program — Renew your air brake endorsement
67. D — The trailer supply valve
Opening the trailer supply valve sends air to open the tractor protection valve; closing it exhausts that air and spring force closes the valve.
Trailer brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 5 Trailer Brake Subsystem, Trailer Brake Subsystem — Tractor protection valve
68. C — Clamp-type chambers
Almost all commercial vehicles use brake chambers held together by a clamp assembly, called clamp-type chambers.
Service brakes and brake chambers · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 3 Service Brake Subsystem, Service Brake Subsystem — Air brake chambers
69. C — Compressed air stored in tanks
Air brakes store compressed air in tanks and use it to apply the brakes at each wheel. Brake fluid is what hydraulic systems use.
How vehicle brakes work · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 1 Vehicle Braking Systems, Vehicle Braking Systems — Air brakes differ from hydraulic brakes
70. B — Weaker brakes as they heat up
As brake components heat up they become less effective and you must press harder to get the same force. That is brake fade.
Speed, weight, heat and ABS · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 7 Demands on Brakes While Driving, Demands on Brakes While Driving — Brake fade
71. C — Note where the gauges stop climbing
Run the engine until pressure reaches its maximum and stops climbing; that is cut-out. An air dryer purge also signals cut-out.
Air brake system tests · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 10 Inspecting Air Brake System Operation, Inspecting Air Brake System Operation — Testing air-compressor governor settings
72. D — There is enough pressure to keep them off
Many vehicles can be driven with spring brakes partly applied, so check that system pressure (normally at least 60 psi) is enough to keep them from applying.
Spring (parking and emergency) brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 4 Spring (Parking and Emergency) Brake Subsystem, Spring Brake Subsystem — Spring brakes for emergency braking and parking
73. D — Air brakes out of adjustment
The truck handbook names out-of-adjustment air brakes as the most common reason. A full air brake pre-trip inspection helps prevent it.
Compliance and safe inspection · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 8 Air Brake Compliance, Daily trip inspection (Truck Handbook)
74. A — So one circuit can stop you if one fails
Air from the supply tank splits into two circuits. Having two is a safety feature: if one fails, the other still provides enough braking to stop.
Air supply subsystem · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 2 Air Supply Subsystem, Air Supply Subsystem — Dual-service tanks
75. C — A malfunctioning brake
Linings must contact the drum when brakes are applied and be clear when released. No contact when applied means the brake is malfunctioning.
Inspecting brake components · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 9 Inspecting Air Brake Components, Inspecting Air Brake Components — Check brake-lining to drum contact
76. B — Measure the applied pushrod stroke
The most reliable method for inspecting brake adjustment is measuring the applied pushrod stroke.
Brake adjustment and pushrod stroke · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 11 Inspecting Air Brake Adjustment, Inspecting Air Brake Adjustment — Brake adjustment must be inspected regularly
77. A — The S-cam drum brake
The S-cam brake, a drum brake, is the most common type on commercial vehicles with air brakes.
Foundation brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 6 Foundation Brakes, Foundation Brakes — "S" cam brakes
78. A — 6 months
Take the referral envelope to a DriveTest centre within 6 months to get your air brake endorsement.
Getting and renewing the Z endorsement · Based on: ontario.ca — Get a truck driver's licence (updated Sept. 2026), Air brake (Z) endorsement program, Air brake (Z) endorsement program — After the course
79. B — Seals together at an angle, then rotated
Place the sealing surfaces against each other at an angle, then rotate them into alignment. Once joined they lock and take real effort to separate.
Trailer brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 5 Trailer Brake Subsystem, Trailer Brake Subsystem — Connecting a trailer
80. D — Wear makes the stroke longer
As brakes wear, the linkage must be readjusted so the pushrod stroke stays within its normal operating range.
Service brakes and brake chambers · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 3 Service Brake Subsystem, Service Brake Subsystem — Air brake chambers
81. A — A rotor and a caliper with pads
Disc brakes use a disc-shaped rotor and a caliper holding pads, which clamp both sides of the rotor.
How vehicle brakes work · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 1 Vehicle Braking Systems, Vehicle Braking Systems — Components of air brakes
82. D — Where you can see it in the mirror
On trailers, ABS indicators are usually placed so they are visible in your rear-view mirror.
Speed, weight, heat and ABS · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 7 Demands on Brakes While Driving, Demands on Brakes While Driving — Anti-lock braking systems
83. C — Apply them, then pull gently in low gear
Apply the spring brakes, remove the chocks and gently apply power in a low gear. The vehicle may rock, but it should not move significantly.
Air brake system tests · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 10 Inspecting Air Brake System Operation, Inspecting Air Brake System Operation — Testing the spring brakes
84. D — Parking and emergency stopping
Spring brakes work when you park and in an emergency when the service brakes fail. Normal stopping is done by the service brakes.
Spring (parking and emergency) brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 4 Spring (Parking and Emergency) Brake Subsystem, Spring Brake Subsystem — Spring brakes for emergency braking and parking
85. D — Safety glasses, steel toes, bump cap
The handbook lists safety glasses, steel-toe shoes and bump caps as proper safety equipment for brake inspections.
Compliance and safe inspection · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 8 Air Brake Compliance, Inspecting Air Brake Components — Inspecting the brake system
86. A — Its debris can hurt eyes and ears
Exhausting air travels very fast and carries moisture, oil, dirt and dust, which can harm the eyes and hearing of anyone in its path.
Air supply subsystem · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 2 Air Supply Subsystem, Air Supply Subsystem — Compressed air can be hazardous
87. D — Spring brakes off, service brakes on
Chambers must be inspected with air pressure applied, meaning spring brakes released and service brakes applied. Leaks can usually be heard.
Inspecting brake components · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 9 Inspecting Air Brake Components, Inspecting Air Brake Components — Inspecting air brake chambers
88. A — 1-3/4 in. (45 mm)
Standard types 16, 20 and 24 all share a 1-3/4 inch (45 mm) limit; their long-stroke L versions allow 2 inches.
Brake adjustment and pushrod stroke · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 11 Inspecting Air Brake Adjustment, Brake Adjustment Limits Chart — Clamp-type chambers
89. B — Shields or backing plates hide them
Components inside the wheel are difficult to see, especially when a dust shield or backing plate protects them.
Foundation brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 6 Foundation Brakes, Foundation Brakes — "S" cam brakes
90. A — An online air brake learning module
Renewals on or after September 1, 2023 require completing the online air brake learning module; the knowledge test is no longer needed for renewal.
Getting and renewing the Z endorsement · Based on: ontario.ca — Get a truck driver's licence (updated Sept. 2026), Air brake (Z) endorsement program, Air brake (Z) endorsement program — Renew your air brake endorsement
91. B — Red and eight-sided
The trailer air supply valve normally has a red, eight-sided knob. The yellow diamond is the spring brake control.
Trailer brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 5 Trailer Brake Subsystem, Trailer Brake Subsystem — Trailer air supply valve
92. D — As a defect needing prompt attention
The Highway Traffic Act strictly regulates pushrod stroke; any brake exceeding the adjustment limit is a defect requiring prompt attention.
Service brakes and brake chambers · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 3 Service Brake Subsystem, Service Brake Subsystem — Air brake chambers
93. B — Heat
Friction between shoes or pads and the drums or rotors converts motion into heat, which the brake parts must absorb and shed. Air pressure only applies the brakes; it is not where the energy goes.
How vehicle brakes work · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 1 Vehicle Braking Systems, Vehicle Braking Systems — Stopping a vehicle
94. C — Press it further
Higher demand means greater brake application pressure is needed, so you must press the pedal further.
Speed, weight, heat and ABS · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 7 Demands on Brakes While Driving, Demands on Brakes While Driving — Vehicle speed and weight
95. D — Report it; that is not normal
A significant amount of moisture from the supply tank may be normal, but significant moisture from the other tanks is not and should be reported.
Air brake system tests · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 10 Inspecting Air Brake System Operation, Inspecting Air Brake System Operation — Testing the air-tank drain valves
96. C — Compress the spring so it can't apply
A technician can manually compress (cage) the spring with a caging bolt, for example to move a vehicle in an emergency. The brake will then not apply.
Spring (parking and emergency) brakes · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 4 Spring (Parking and Emergency) Brake Subsystem, Spring Brake Subsystem — Disabling the spring-brake chamber
97. A — Only if spring brakes or blocks hold it
Never leave the driver's seat or get under a vehicle unless its spring brakes are applied or the wheels are securely blocked.
Compliance and safe inspection · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 8 Air Brake Compliance, Inspecting Air Brake System Operation — Secure the vehicle
98. D — Where the compressor resumes pumping
Cut-in is the point where the governor makes the compressor resume pumping after pressure has dropped. Cut-out is where it stops.
Air supply subsystem · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 2 Air Supply Subsystem, Air Supply Subsystem — Governor
99. C — Looking at visible parts
It mainly means looking to see that each visible component is free of apparent defects or abnormalities. Never dismantle brake parts.
Inspecting brake components · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 9 Inspecting Air Brake Components, Inspecting Air Brake Components — Inspecting the brake system
100. C — By 19 mm or more
The chamber type affects the adjustment limit, which can vary by 19 millimetres or more between standard and long-stroke chambers.
Brake adjustment and pushrod stroke · Based on: MTO Air Brake Handbook (online edition, Feb. 2026), Ch. 11 Inspecting Air Brake Adjustment, Inspecting Air Brake Adjustment — Long-stroke brake chambers

Original practice questions by Canada Exam Prep, written from the official handbook. Not official test questions. Free to print for personal study.

FAQ

Air brake test questions and answers (printable): common questions

Is this the official air brake test in PDF form?

No. The real test questions are not published. These are our own questions, written from the Official Air Brake Handbook, which you can read free on ontario.ca.

Where are the explanations?

The printable sheet shows only the answer key so it stays short. Every question has a full explanation and a handbook citation in the interactive practice tests and topic pages.

How should I use a printed air brake test?

Answer all 100 without looking, mark them with the key, then reread the handbook chapter for each topic where you missed more than one.

Ontario Air Brake Test Questions and Answers – Printable