Ontario Air Brake (Z) Mock Exam 3

All 25 questions in this test

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

1. For the build-up test, what engine speed is used?

   1. 600 to 900 rpm
   2. 1,200 to 1,500 rpm
   3. 300 to 500 rpm
   4. Full governed rpm

2. 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

3. 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

4. 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

5. 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

6. Which habit helps keep brake temperatures down?

   1. Leaving a safe following distance
   2. Coasting in neutral down long grades
   3. Riding the brake lightly on all hills
   4. Braking hard and late at every stop

7. Below what supply-line pressure must trailer spring brakes apply automatically?

   1. 60 psi (414 kPa)
   2. 120 psi (828 kPa)
   3. 20 psi (138 kPa)
   4. 90 psi (621 kPa)

8. 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

9. Why must both brake chambers on a steering axle be the same size?

   1. The law sets one size per truck
   2. Different sizes cannot be bought
   3. Unequal force can affect steering
   4. Larger chambers use more air

10. After the renewal learning module, what do you bring to DriveTest?

    1. A brand-new medical report form only
    2. Completion certificate and licence
    3. Your last pushrod stroke measurements
    4. A letter from your current employer

11. 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

12. How long should you drain the supply tank during the drain valve check?

    1. Until the low-air light comes on
    2. For exactly ten seconds
    3. Until pressure reaches 60 psi
    4. Until only clean air comes out

13. What happens to a vehicle when a wheel locks and the tire skids?

    1. Its air pressure rises
    2. It stops in a shorter distance
    3. It loses steering control and stability
    4. It automatically engages ABS on all axles

14. What do engine brakes and retarders help you avoid?

    1. Pushrod measurement
    2. Compressor cut-in
    3. Low tire pressure
    4. Excessive brake temperature

15. When can you book the Z practical test?

    1. Only after one year of driving
    2. Before writing the knowledge test
    3. After passing the knowledge test
    4. Only with a Class A licence

16. 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)

17. When you release the brake pedal, what returns the pushrod into the chamber?

    1. The spring inside the chamber
    2. The weight of the slack adjuster
    3. Air from the secondary tank
    4. The governor at cut-in

18. 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

19. You use the hand valve and the brake pedal at the same time. What pressure reaches the trailer?

    1. Only the hand valve pressure
    2. The two added together
    3. The higher of the two
    4. The lower of the two

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. 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

22. When do the trailer service brakes apply?

    1. Only when the tractor is parked
    2. Only when the hand valve is used
    3. Only below 60 psi
    4. Whenever the brake pedal is pressed

23. Which danger should you avoid while inspecting an air brake system?

    1. Touching the dash gauges
    2. Looking at the brake chamber labels
    3. Reading the inspection schedule
    4. Standing in the path of exhausting air

24. What is the most visible and permanent sign of a long-stroke brake chamber?

    1. Square air ports
    2. A yellow clamp
    3. Round air ports
    4. A blue pushrod

25. 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