Ontario Air Brake (Z) Practice Test 6

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. Once pushrod stroke passes the adjustment limit, what happens to brake force?

   1. It stays at full strength
   2. It increases slightly
   3. It falls off rapidly toward zero
   4. It shifts to the other axle

2. 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

3. 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

4. What does the spring brake control valve knob normally look like?

   1. Green and square
   2. Blue and round
   3. Yellow and four-sided
   4. Red and eight-sided

5. 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

6. Over which pressure range is build-up time measured?

   1. From 85 to 100 psi
   2. From 0 to 60 psi
   3. From 60 to 90 psi
   4. From 100 to 145 psi

7. 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

8. What does a service brake priority trailer guarantee?

   1. Springs release before any air arrives
   2. Service air comes before springs release
   3. The trailer never needs its tanks drained
   4. Brakes apply only through the hand valve

9. 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

10. 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

11. 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

12. In a dual-circuit service brake system, what happens if one circuit fails?

    1. Wheels on the other circuit still brake
    2. The compressor feeds the failed side
    3. All service brakes stop working
    4. Only the trailer brakes still work

13. 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

14. An air hose shows wear through its outer cover into the reinforcing layer, but no leak yet. Is it defective?

    1. Only if it is a trailer supply hose
    2. No, unless the inner layer shows too
    3. No, only leaking hoses are defects
    4. Yes, it is a defect

15. How many air line connections does a DD3 brake chamber have?

    1. Three
    2. Two
    3. One
    4. Four

16. During the practical exam, what should you tell the examiner?

    1. The truck's purchase price
    2. What you are testing at each step
    3. Your years of driving experience
    4. Nothing; work silently

17. 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

18. 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

19. How does the brake system of a converter dolly compare with a trailer's?

    1. It has no brakes at all
    2. It has only spring brakes
    3. It uses hydraulic brakes only
    4. It is essentially the same

20. You cannot complete the air brake learning module online. What can you do?

    1. Skip it and renew anyway
    2. Take the old written test at home
    3. Ask your employer to sign for you
    4. Complete it in person at DriveTest

21. 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

22. In extreme cases, what can severe brake fade lead to?

    1. Higher air pressure in the tanks
    2. Automatic release of spring brakes
    3. Being unable to slow or stop
    4. Shorter stopping distances

23. Why does water collect at the bottom of air tanks?

    1. The air dryer adds water vapour to it
    2. Brake fluid separates in cold weather
    3. Rain gets in through open gladhands
    4. Moisture condenses as air is compressed

24. 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

25. Who may readjust manual or automatic slack adjusters, according to the handbook?

    1. Only certified people
    2. Any licensed Z driver
    3. The vehicle owner at any time
    4. Any DriveTest examiner