Chapter 12b: Checklists, Charts and Circuit Diagrams

A free Ontario air brake practice test featuring the “Checklists” chapter is an excellent resource for drivers preparing for their air brake certification.

Ontario Air Brake Test - Chapter 12b: Checklists, Charts and Circuit Diagrams

1 / 25

In the spring brake holding test, what should you do after applying the spring brakes and removing wheel chocks?

Fan the brakes to reduce pressure

Drive the vehicle forward at low speed

Turn off the air compressor

Gently apply engine power and observe the vehicle response

2 / 25

Before inspecting brake adjustment, what minimum air pressure must be ensured?

Below 621 kPa (90 psi)

Above 345 kPa (50 psi)

Exactly 690 kPa (100 psi)

Above 621 kPa (90 psi)

3 / 25

To set the correct test pressure for brake adjustment, to what range must both primary and secondary gauges be adjusted?

690 to 827 kPa (100 to 120 psi)

621 to 690 kPa (90 to 100 psi)

345 to 414 kPa (50 to 60 psi)

Below 414 kPa (60 psi)

4 / 25

When inspecting the supply tank drain valve, what should you do?

Drain until the low-air warning activates

Drain only enough to turn off the compressor

Drain the supply tank until it discharges only clean air

Do not drain the supply tank during inspections

5 / 25

What information must be identified for each brake chamber when checking adjustment limits?

Chamber size, chamber type, and adjustment limit

Chamber color, vehicle make, and load weight

Tire size, axle ratio, and brake lining thickness

Tank size, governor setting, and compressor type

6 / 25

When testing the automatic application of the trailer spring brakes, what must be true before closing the trailer supply valve?

Only the primary system is pressurized

Trailer is disconnected and brakes are released

Trailer supply valve is open, air pressure is normal, and trailer is fully charged

The engine is shut off and keys removed

7 / 25

When testing the tractor (towing vehicle) protection valve, what must you ensure first?

Spring brakes are caged

Air pressure is within its normal operating range

Trailer air-tanks are empty

Service brakes are fully released

8 / 25

What is the legal status of operating or driving a defective vehicle?

It is illegal

It is allowed for short distances only

It is allowed with supervisor permission

It is permitted if unloaded

9 / 25

What sound should you hear when the trailer spring brakes apply automatically during the test?

Air exhausting from the trailer spring brakes

A clicking sound at the relay valve

A steady hiss at the dash

No sound at all

10 / 25

In Method 2 of inspecting brake adjustment, what is measurement number 1?

The released position distance from a point on the pushrod to a fixed point at the brake chamber

The difference between two applied measurements

The stroke limit from the chart

The applied position distance only

11 / 25

What is the required action if any air-tank drain valve fails to function properly?

Tap it lightly and continue driving

Add more air pressure and retest later

Ignore it if the vehicle feels normal

Consider the vehicle defective and do not operate it

12 / 25

Before inspecting air-tank drain valves, what must you confirm about system pressure?

It is within its normal operating range

It is below the low-air warning level

It is at 0 kPa (0 psi)

It is at maximum governor cut-out only

13 / 25

During the tractor protection valve test, where should you place the trailer service-line coupler?

Connected to the supply line

Back into its storage bracket

On the ground away from the vehicle

Where it can be observed

14 / 25

How do you start the test for automatic trailer spring brake application?

Close (pull out) the trailer supply valve

Pump the brake pedal until low air warning comes on

Disconnect the service line

Drain all trailer air-tanks

15 / 25

During the spring brake test, what indicates a defective vehicle?

The engine stalls when power is applied

The compressor cycles frequently

The spring brakes fail to hold the vehicle stationary

The wheels spin without moving the vehicle

16 / 25

When inspecting brake adjustment, what indicates that the vehicle is defective?

All strokes are slightly below the limit

Strokes vary slightly between axles

Any brake pushrod stroke exceeds the specified adjustment limit

Only one brake has a shorter stroke than others

17 / 25

What are drivers required to do when they find defective vehicle conditions?

Continue driving until the end of the shift

Repair them personally before reporting

Only note them for the next inspection

Report defective vehicle conditions

18 / 25

What should you observe while draining the remaining air-tanks during the drain valve inspection?

That each drain valve functions properly

That the tanks empty in less than 10 seconds

That no air discharges from any tank

That only oil discharges from each tank

19 / 25

In Method 1 of inspecting brake adjustment, what do you do to the pushrod?

Mark the pushrod at the brake chamber or a suitable fixed reference point

Grease the pushrod thoroughly

Remove the pushrod from the chamber

Bend the pushrod slightly for reference

20 / 25

When testing the spring (parking/emergency) brakes, what is the first action?

Apply the spring brakes

Increase engine RPM

Apply full service brake pressure

Remove the trailer

21 / 25

During the automatic trailer spring brake application test, what does it mean if the trailer spring brakes do not apply?

The trailer is simply not loaded

The air tanks are overfilled

The vehicle is defective

The vehicle is safe to operate

22 / 25

While testing the tractor protection valve, what indicates the vehicle is defective?

The trailer supply valve will not move

Air exhausts from the trailer service-line coupler when the brake pedal is pressed

The spring brakes remain applied

No air is heard anywhere in the system

23 / 25

Before checking brake adjustment, what must be done with the spring (parking) brakes?

Release spring brakes

Cage all spring brakes

Partially apply spring brakes

Apply spring brakes fully

24 / 25

How is the applied pushrod stroke calculated in Method 2?

Subtract measurement number 1 from measurement number 2

Divide measurement number 2 by measurement number 1

Add measurement number 1 and measurement number 2

Multiply measurement number 1 by measurement number 2

25 / 25

Before testing the tractor protection valve, what must be the position of the trailer supply valve?

Closed (pulled out)

Open (pushed in)

It does not matter

Partially open

Your score is

This practice test helps users become familiar with the step-by-step procedures required for thorough air brake inspections. By reviewing sample checklist questions, drivers learn to systematically check air pressure, warning devices, brake adjustment, and air leaks, ensuring nothing is missed during actual inspections. Regular practice with these tests builds confidence, reinforces knowledge, and prepares candidates for the official exam. Utilizing free practice tests is an effective way to master checklist procedures and promote road safety for all drivers.