ICBC Air Brake Test Practice (Code 15)

All 50 questions in this test

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

1. At fast idle, how quickly must the compressor build pressure from 50 to 90 p.s.i.?

   1. Within 30 seconds
   2. Within three minutes
   3. Within one minute
   4. Within ten minutes

2. How often must you check manual and automatic slack adjusters?

   1. Only when the brakes feel weak
   2. Weekly, at the yard
   3. Only at the annual inspection
   4. Daily, during the pre-trip inspection

3. For a single-unit truck, what air loss is allowed during the one-minute leakage test?

   1. 6 p.s.i. per minute
   2. 1 p.s.i. per minute
   3. 4 p.s.i. per minute
   4. 3 p.s.i. per minute

4. The foot valve sends a 20 p.s.i. signal to a relay valve. What pressure does the relay valve deliver to the chambers?

   1. About 100 p.s.i.
   2. About 40 p.s.i.
   3. About 20 p.s.i.
   4. About 10 p.s.i.

5. On which axles are spring parking brakes mounted?

   1. Trailer axles only
   2. All axles
   3. Steering axles only
   4. Rear axles only

6. Within what tractor pressure range must trailer air shut off automatically?

   1. 20 to 45 p.s.i.
   2. 90 to 100 p.s.i.
   3. Below 5 p.s.i.
   4. 60 to 90 p.s.i.

7. Why can an air brake system tolerate a small leak better than a hydraulic one?

   1. Air brakes have no lines to leak
   2. Hydraulic fluid evaporates faster
   3. Air cannot escape through small holes
   4. The compressor keeps making more air

8. Does a 90-degree slack adjuster angle when applied prove the brake is adjusted?

   1. Yes, on automatic adjusters
   2. No; it depends on pushrod length
   3. Yes, a 90-degree angle always proves adjustment
   4. Only on trailer axles

9. At what pressure should the low-air warning come on during the pump-down?

   1. Exactly 80 p.s.i.
   2. At or below 40 p.s.i.
   3. At or above 60 p.s.i.
   4. At 20 p.s.i.

10. What does a dual foot valve do?

    1. Controls the spring brakes
    2. Doubles the braking force at every wheel
    3. Splits the system into two sections
    4. Supplies the trailer only

11. Which parking brake cannot be compounded?

    1. An s-cam drum brake
    2. A safety actuator
    3. A wedge brake
    4. A spring parking brake

12. Which line fills the trailer reservoirs at full tractor pressure?

    1. The supply (emergency) line
    2. The electrical cable
    3. The control (service) line
    4. The hydraulic line

13. With an air dryer fitted, should you still drain the reservoirs?

    1. Only if the dryer fails
    2. Only in summer
    3. Yes, regularly
    4. No, never

14. Since when have all air-braked commercial trucks and trailers been built with automatic slack adjusters?

    1. 1980
    2. 2000
    3. 1996
    4. 2010

15. Why do the leakage test with the parking brakes released?

    1. To check the low-air warning
    2. To avoid compounding
    3. To save fuel
    4. To hear the compressor

16. The primary section of a dual system fails. Which brakes still apply?

    1. Only the drive axle brakes
    2. Only the steering axle brakes
    3. All brakes normally
    4. No brakes at all

17. What must you do before caging a spring brake?

    1. Release the service brakes
    2. Drain the wet tank
    3. Block the wheels
    4. Start the engine

18. What must every trailer's emergency system do if the trailer separates?

    1. Release all trailer brakes
    2. Fully apply the trailer brakes
    3. Lower the landing gear
    4. Sound a warning horn

19. In an s-cam brake, what spreads the linings against the drum?

    1. The s-shaped head of the camshaft
    2. A wedge between rollers
    3. The brake shoe return springs
    4. Hydraulic pistons

20. Who is ultimately responsible for brake adjustment before the vehicle moves?

    1. The maintenance crew
    2. The driver
    3. The vehicle owner only
    4. The CVIP inspector

21. Between what pressures must the governor stop the compressor pumping?

    1. 90 and 100 p.s.i.
    2. 60 and 80 p.s.i.
    3. 135 and 150 p.s.i.
    4. 105 and 135 p.s.i.

22. How many reservoirs do most dual air brake systems have?

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

23. Why is it illegal to park a vehicle using air pressure alone?

    1. A leak could release the brakes
    2. It overheats the brake drums
    3. It wears out the compressor
    4. It drains the battery

24. What is the trailer hand valve meant for?

    1. Emergency stops at highway speed
    2. Applying only the trailer brakes, such as when coupling
    3. Normal braking in traffic
    4. Parking the trailer overnight on a slight grade

25. The ABS warning light stays on while you drive. What does this mean?

    1. All braking has failed and you must stop now
    2. The air pressure is too high
    3. The parking brakes are applied
    4. ABS has failed, but normal brakes still work

26. May you retrofit manual slack adjusters on a vehicle built with automatic ones in B.C.?

    1. Yes, on trailers only
    2. No, it is illegal
    3. Yes, with a mechanic's note
    4. Yes, if they are new

27. During the pump-down, before what pressure must the governor cut in?

    1. 100 p.s.i.
    2. 80 p.s.i.
    3. 45 p.s.i.
    4. 60 p.s.i.

28. The low-air warning comes on while you drive. What should you do?

    1. Release the spring brakes
    2. Keep going to the next town
    3. Pump the brakes to raise pressure
    4. Stop and find the cause before going on

29. How are spring brakes applied and released?

    1. Applied by hydraulic pressure
    2. Applied by air, released by spring
    3. Applied by spring force, released by air
    4. Applied and released by air

30. How long must dynamited brakes on a trailer without spring brakes stay applied?

    1. At least 15 minutes
    2. At least one hour
    3. At least 2 minutes
    4. Until the driver releases them

31. Your reservoirs hold 80 p.s.i. What is the most application pressure you can get?

    1. 80 p.s.i.
    2. 160 p.s.i.
    3. 100 p.s.i.
    4. 120 p.s.i.

32. While adjusting a manual slack adjuster, the pushrod starts coming out of the chamber. What does that mean?

    1. You are turning the bolt the wrong way
    2. The brake is correctly adjusted
    3. The chamber diaphragm has failed
    4. You should keep turning harder

33. You drain only the supply reservoir and the primary gauge also drops. What might be faulty?

    1. A one-way check valve
    2. The safety valve
    3. The governor
    4. The foot valve

34. What is the purpose of a quick release valve?

    1. To fill the trailer reservoirs
    2. To apply the brakes faster in an emergency
    3. To lock the brakes when parked
    4. To exhaust air close to the chambers

35. What is compounding?

    1. Using the hand valve and the foot valve at the same time
    2. Draining two reservoirs at once
    3. Heavy service braking on top of applied spring brakes
    4. Connecting two trailers to one tractor

36. Which colour usually marks the control (service) glad hand?

    1. Blue
    2. Yellow
    3. Red
    4. Green

37. What does the governor do when system pressure reaches cut-out?

    1. Applies the spring brakes
    2. Unloads the compressor
    3. Opens the safety valve
    4. Shuts off the engine to save fuel

38. Why can a poorly adjusted brake fail on a long downgrade even if it seemed fine when cool?

    1. The linings swell and lock
    2. The slack adjuster tightens itself
    3. Hot air raises system pressure past the safety valve
    4. Hot drums expand and the chamber bottoms out

39. What application pressure is held during the leakage test?

    1. 90 to 100 p.s.i. for one minute
    2. Full pressure for ten minutes
    3. 20 p.s.i. for five minutes
    4. 60 p.s.i. for 30 seconds

40. A line rupture empties the primary reservoir. What protects the secondary reservoir?

    1. The safety valve
    2. The one-way check valve
    3. The quick release valve
    4. The governor

41. What is blended air in a dual system?

    1. Air from the compressor and the wet tank
    2. Parking control fed by the higher reservoir
    3. Air shared between tractor and trailer
    4. Air mixed with alcohol vapour to stop freezing

42. The trailer spring brakes will not release and the service brakes do not work. What is a likely cause?

    1. The landing gear is down
    2. The supply and control lines are reversed
    3. The trailer is overloaded on its rear axle
    4. The ABS lamp has failed

43. Why is the supply reservoir called the wet tank?

    1. It holds the alcohol anti-freeze
    2. Water and oil sludge collect in it
    3. It is mounted under the fuel tank
    4. It is filled with brake fluid

44. Using the applied stroke method on a Type 30 chamber, when does the brake need adjusting?

    1. When applied stroke is 1 inch
    2. When applied stroke is under ½ inch
    3. When applied stroke is 1¼ inches
    4. When applied stroke exceeds 1¾ inches

45. Which reservoir must be drained on the road test?

    1. The secondary reservoir only
    2. The trailer reservoir only
    3. None; draining is optional
    4. The supply (wet) reservoir

46. In many dual systems, which brakes does the primary section work?

    1. The drive (rear) axle brakes
    2. The spring parking brakes
    3. The steering axle brakes
    4. The trailer brakes only

47. At what system pressure may spring brakes apply fully on their own?

    1. Between 60 and 80 p.s.i.
    2. Only at zero p.s.i.
    3. Between 90 and 100 p.s.i.
    4. Between 20 and 45 p.s.i.

48. How should you park a tractor-trailer?

    1. Apply the trailer hand valve, then leave the engine running
    2. Leave it in gear with the engine idling
    3. Tractor brakes set, trailer supply closed, wheels blocked
    4. Pump the foot valve and set the hand valve

49. A compressor belt deflects more than double its width when pressed between pulleys. What does this mean?

    1. It is too tight
    2. It needs adjusting
    3. It is correctly tight
    4. It must be replaced only if cracked

50. What does a visible red marking on a new pushrod mean?

    1. The brake was adjusted correctly this morning
    2. The brake is badly out of adjustment
    3. The pushrod is the wrong size
    4. The chamber is a long-stroke type