Ontario Air Brake (Z) Practice Test 11

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. A tractor is hauling a single semi-trailer. How much air loss per minute is allowed during the applied-brake test?

   1. 8 psi (55 kPa)
   2. 6 psi (41 kPa)
   3. 3 psi (21 kPa)
   4. 4 psi (28 kPa)

2. 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

3. 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)

4. 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

5. 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

6. How does an air compressor raise the pressure of air?

   1. By mixing it with alcohol vapour first
   2. By squeezing it into a smaller space
   3. By heating it inside the supply tank
   4. By cooling it as it passes the air dryer

7. 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

8. 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

9. 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

10. Testing the tractor protection valve, which valve position and line do you set up?

    1. Supply valve closed, service line disconnected
    2. Hand valve applied, gladhands joined
    3. Supply valve open, both lines connected
    4. Supply valve closed, supply line removed

11. 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

12. What stops air from flowing back into the supply tank?

    1. One-way check valves
    2. The drain valve
    3. The safety valve
    4. The governor

13. 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

14. 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

15. 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

16. What do the dash air pressure gauges show?

    1. Pressure inside each brake chamber
    2. Pushrod stroke at each of the wheels
    3. Air temperature inside the compressor
    4. Primary and secondary tank pressure

17. 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)

18. Why might a driver not notice brakes that are slightly out of adjustment?

    1. Normal driving rarely needs full braking
    2. The ABS light hides the problem
    3. Out-of-adjustment brakes feel stronger
    4. Spring brakes cover the difference

19. Which tank does compressed air enter first?

    1. The trailer reservoir
    2. The primary tank
    3. The supply (wet) tank
    4. The secondary tank

20. During the air-loss test, how do you treat the first drop when you press the pedal?

    1. Add it to the result of the next minute
    2. Restart the test after each drop
    3. Ignore it; time after it settles
    4. Count it as part of the loss

21. Which list matches the parts of a wedge air brake?

    1. Camshafts, rollers, slack adjusters and pads
    2. Rotors, calipers, pads and chambers
    3. Rotors, wedges, rollers and anchor pins
    4. Drums, shoes, spiders, shields and chambers

22. What is the lowest actual cut-in pressure allowed?

    1. 100 psi (690 kPa)
    2. 55 psi (380 kPa)
    3. 60 psi (414 kPa)
    4. 80 psi (552 kPa)

23. What is a wig wag?

    1. A valve that drains the wet tank
    2. A knob that releases the trailer brakes
    3. An arm that drops when air is low
    4. A gauge that shows pushrod stroke

24. 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

25. You find oil in a tank other than the supply tank. What is the concern?

    1. Brake system contamination
    2. The compressor is running too cold
    3. The tank needs a larger drain valve
    4. Nothing; the oil lubricates the valves