Ontario Air Brake (Z): How vehicle brakes work

All 18 questions in this test

Every question and its answer choices. The correct answers and explanations appear when you take the test above.

1. 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

2. 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

3. In a drum brake, how do the brake shoes stop the wheel?

   1. They push inward on the hub
   2. They squeeze a band around the axle
   3. They clamp both sides of a rotor
   4. They press outward against the drum

4. Which statement about brake reaction time in air brake systems is true?

   1. Delay occurs only when releasing the pedal
   2. Delay happens only on older or worn trucks
   3. All air systems have a short delay
   4. Modern valves remove all delay completely

5. One brake on a tractor is not working. What happens to the others?

   1. They apply with less force to balance
   2. They adjust automatically to cover it
   3. Nothing, each wheel brakes independently
   4. They do more work and can overheat too

6. A school bus has hydraulic service brakes and an air-operated parking brake. Is a Z endorsement needed?

   1. Yes, but only when the bus carries children
   2. No, air parking brakes alone don't need one
   3. Yes, any air component at all requires it
   4. Only if the air tank is larger than 50 litres

7. Air-over-hydraulic brakes are found mainly on which vehicles?

   1. Highway tractor-trailers only
   2. Motorcycles and mopeds
   3. Passenger cars and vans
   4. Medium-duty commercial vehicles

8. 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

9. 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

10. What does the handbook call the brake hardware located at the wheels?

    1. Foundation brake components
    2. Air supply components
    3. Control valve components
    4. Service circuit components

11. 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

12. 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

13. Your brakes overheated on a long grade. What does the handbook advise?

    1. Spray the drums with cold water at once
    2. Keep driving so the airflow cools them
    3. Pump the pedal to spread the heat around
    4. Stop, let them cool, check all brakes

14. 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

15. Which result of too much brake heat is listed in the handbook?

    1. Faster compressor cut-in
    2. Longer pushrod life
    3. A tire fire
    4. Higher air pressure

16. Which kind of brake system is used on almost all cars and light trucks?

    1. Air-over-hydraulic brakes
    2. Air brakes
    3. Spring brakes only
    4. Hydraulic brakes

17. Why are air brakes used on large commercial vehicles?

    1. They send high forces over long distances simply
    2. They never need a daily inspection by law
    3. They work without any engine-driven compressor
    4. They stop faster than any hydraulic system

18. 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