Ontario Air Brake (Z): Spring (parking and emergency) brakes

All 21 questions in this test

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

1. Your service brakes fail on the road. How can you use the spring brakes to stop?

   1. Use the spring brake control valve
   2. Open all the air tank drain valves
   3. Shut off the engine to drop the air
   4. Pull the trailer hand valve fully on

2. What does it mean to cage a spring brake?

   1. Lock the spring brake fully applied
   2. Drain all the air from the spring section
   3. Compress the spring so it can't apply
   4. Replace the diaphragm with a new one

3. On most vehicles, how do you release the spring brakes with the control valve?

   1. Turn the knob a quarter turn
   2. Push the knob in to supply air
   3. Pull the knob out to exhaust air
   4. Press the brake pedal three times

4. How do you release DD3 parking brakes?

   1. Push the blue knob, then start the engine
   2. Pull the valve, then pump the pedal twice
   3. Turn the caging bolt one full turn out
   4. Operate the valve, then hold the pedal 3–5 s

5. Spring brakes are designed for which two jobs?

   1. Normal stops and slowing on hills
   2. Anti-lock control and steering
   3. Trailer coupling and uncoupling
   4. Parking and emergency stopping

6. What provides the force in a spring brake chamber?

   1. A hydraulic piston
   2. A rubber diaphragm and air
   3. An electric solenoid
   4. A large coil spring

7. Where are DD3 safety actuators commonly used?

   1. On farm tractors
   2. On converter dollies only
   3. On light pick-up trucks
   4. On buses and motor coaches

8. Some tractors have a round blue knob. What does it control?

   1. The front wheel-limiting valve
   2. The trailer supply line
   3. The air dryer purge
   4. The tractor's spring brakes only

9. 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

10. Why should you never try to repair a spring brake chamber yourself?

    1. It would void the vehicle's CVOR
    2. It is filled with corrosive fluid
    3. It is welded shut and cannot be opened
    4. Its spring can release violently

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

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

12. How are spring brakes applied?

    1. By brake fluid from a master cylinder
    2. By air pushed into the service chamber
    3. By a spring when air leaves the chamber
    4. By the driver pulling a cable lever

13. Air pressure drops below about 60 psi while driving. What does the control valve do?

    1. Locks the spring brakes in the released position
    2. Exhausts air so spring brakes apply
    3. Opens the supply tank safety valve
    4. Switches over to using the trailer's air

14. 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

15. How can you recognize a spring brake chamber compared with a service chamber?

    1. It has no pushrod coming out of it
    2. It is painted red by Ontario law
    3. It is mounted inside the brake drum
    4. It has an extra, larger spring section

16. In a spring brake chamber, which section is nearest the pushrod end?

    1. The caging bolt section
    2. The spring brake section
    3. The service brake section
    4. The diaphragm vent section

17. During your inspection you see a caging bolt sticking out of a chamber. What should you do?

    1. Drive on; it means the brake is adjusted
    2. Remove the bolt yourself before leaving
    3. Note it for the next annual inspection
    4. Have the vehicle inspected and repaired now

18. Before driving, what should you confirm about air pressure and the spring brakes?

    1. Pressure is below 60 psi to save fuel
    2. The service section is empty of air
    3. The springs are caged for the whole trip
    4. There is enough pressure to keep them off

19. 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

20. System pressure is 45 psi and you try to drive off. What is likely happening?

    1. The spring brakes are partly applied
    2. The governor is at cut-out
    3. The service brakes are locked on
    4. The trailer supply valve is open

21. About how much air pressure is normally needed to hold spring brakes released?

    1. 20 psi (138 kPa)
    2. 100 psi (690 kPa)
    3. 150 psi (1035 kPa)
    4. 60 psi (414 kPa)