Ontario Air Brake (Z): Foundation brakes

All 19 questions in this test

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

1. 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

2. Which statement about wedge brakes is correct?

   1. They have fully exposed brake linkage
   2. They are designed to be self-adjusting
   3. They use an S-shaped camshaft head
   4. They are a type of air disc brake

3. 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

4. Which of these S-cam parts is located inside the wheel rather than outside?

   1. The camshaft rollers
   2. The slack adjuster
   3. The brake chamber
   4. The pushrod

5. Can one vehicle use more than one type of foundation brake?

   1. Only on trailers, never on the tractor
   2. Yes, designs can be mixed on one vehicle
   3. No, all axles must use the same type
   4. Only if all of them are self-adjusting

6. 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

7. What job does the return spring do inside an S-cam brake?

   1. Holds the brake applied when parked
   2. Pushes the pushrod out of the chamber
   3. Pulls shoes back, keeps rollers on cam
   4. Locks the camshaft during a hard stop

8. 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

9. 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

10. 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

11. 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

12. Why is the rotor of an air disc brake only partly visible?

    1. The wheel, caliper and shields hide it
    2. It sits inside the air brake chamber
    3. It is sealed inside a separate brake drum
    4. It is mounted behind the vehicle's fuel tank

13. An S-cam brake is which basic kind of brake?

    1. A band brake
    2. A wedge brake
    3. A drum brake
    4. A disc brake

14. In an S-cam brake, what does the pushrod stroke move first?

    1. The return spring inside the drum
    2. The slack adjuster on the camshaft
    3. The anchor pin mounted in the spider
    4. The brake shoes directly at the drum

15. 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

16. What forces the brake shoes against the drum in an S-cam brake?

    1. The S-shaped cam on the camshaft
    2. A caliper squeezing both of the shoes
    3. A wedge pushed in by the pushrod
    4. Hydraulic pistons inside each shoe

17. 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

18. Anchor pins in an S-cam brake are used to do what?

    1. Hold the brake chamber to its bracket
    2. Join the pushrod to the slack adjuster
    3. Lock the drum to the axle
    4. Attach one end of each brake shoe

19. How does pushrod stroke stop the wheel on an air disc brake?

    1. It spreads shoes inside a drum
    2. It drives a wedge between shoes
    3. It turns an S-cam against rollers
    4. It presses the pads against the rotor