Air Brake Practice Test 04

The free Air Brake Practice Test provides detailed explanations of the correct answers, allowing you to learn from your mistakes and hone your knowledge in areas where you need extra help. By taking advantage of this valuable tool, you’ll be well-equipped to pass the official air brake test and advance your driving career.

1 / 30

Parking brakes should be in what position before making a service brake application?

The resting position

The release position

The forward position

The activated position

2 / 30

How are the brakes caged?

With a twist of the release valve

With a bolt that runs beside the chamber body

With a valve that releases the spring

With a bolt that runs through the centre of the chamber body, which is turned to compress the spring

3 / 30

The control valve is set in what position for dry road surfaces?

Wet

Smooth

Normal

Rough

4 / 30

The spring parking brake system can also act as what?

Air-over hydraulic brakes

Hydraulic brakes

An emergency brake

Service brakes for the trailers

5 / 30

During normal service brake operation, wat happens to the parking brake spring?

It does expand

Nothing happens

It does not expand

It retracts

6 / 30

What should always be done when caging the parking brake spring?

Draining the wet tank

Blocking the wheels

Releasing the two-way valve

Turning off the compressor

7 / 30

Where does the air in the control line 'dead end' to?

The quick release valve

The one-way valve

The two-way valve

The relay valve

8 / 30

How many uses does the relay valve have?

One

Four

Two

Three

9 / 30

Some spring parking brakes can be released mechanically by doing what?

Turning them down

Letting them cool

Turning them up

Winding them off

10 / 30

Spring parking brake chambers should never be disassembled without first doing what?

Finding out which spring has to be caged

Compressing the spring with a caging bolt

Releasing the air pressure

Releasing the spring

11 / 30

Is the installation of spring parking brakes and their piping arrangements done the same in all vehicle air brake systems?

All but fire trucks

Yes

All but tandem trailers

12 / 30

What should the brake chamber be fitted with to ensure debris will not enter the chamber?

A filter

A dust cap

Nothing

A fan

13 / 30

Some systems may have an additional valve controlled by a blue button that applies what?

The trailer spring brakes

The trailer service brakes

None of these

Only the tractor spring parking brakes and not the trailer spring parking brakes

14 / 30

With an automatic limiting valve, brake applications between 40 psi and 60 psi are reduced to...

Less than 60%

Less than 45%

Less than 50%

Less than 20%

15 / 30

Disassembly of a spring brake chamber should be done by...

The driver

All of the above

A qualified mechanic or technician

The vehicle owner

16 / 30

Which statement is false? How quickly the spring brakes will stop the vehicle depends on such factors as...

The weight and speed of the vehicle

The adjustment of the service brakes

The spring force of the spring brakes that have been installed

The type of spring brakes

17 / 30

On the pre-trip air brake inspection, you must ensure that the parking brake spring is not...

Missing

Manually caged

Expanded

Wrong size

18 / 30

Instruction on how to cage is usually found where?

On the body of the parking brake chamber

With the vehicle's manual

From a licensed mechanic

From the carrier

19 / 30

What is the danger of disassembling a spring parking brake unit?

Springs are under extreme pressure and could cause serious personal injury if disassembly is attempted

They could break

There is no danger

They could get stuck

20 / 30

Which statement is false? When parking a vehicle with over heated brakes...

Block the wheels

Stop the engine and leave the transmission in the lowest gear

Keep the engine running between 600 and 900 rpm

Park on level ground

21 / 30

Anytime the reservoir pressure drops to approximately 35 psi, what happens?

The pressure gauge activates

A warning light activates

The spring parking brakes will be activated

Nothing

22 / 30

The effectiveness of the spring parking brake depends on what?

The type of brakes

The size of the spring

The service brake adjustment

The pressure the spring provides

23 / 30

After overheating the brake drums, when should you set the spring parking brake?

The brake temperature gauge has a level reading

The brakes no longer grab

After you have verified the brake drum is cool to the touch

There is no longer any smoke coming from the brakes

24 / 30

What is meant by compounding?

The force applied by the service brakes when the vehicle is fully stopped

The force applied by the spring brakes and the service brake

The force applied by the spring brakes when the vehicle is still in motion

The force applied when the air pressure is below 35 psi

25 / 30

What is an automatic limiting valve?

It will hold off brake application to the front wheels from 25 to 30 psi, depending on how it has been pre-set

It will hold off brake application to the front wheels from 0 to 10 psi, depending on how it has been pre-set

It will hold off brake application to the front wheels from 35 to 40 psi, depending on how it has been pre-set

It will hold off brake application to the front wheels from 15 to 20 psi, depending on how it has been pre-set

26 / 30

What is another word for when the spring compresses?

Cages

Shrinks

Downsizes

Pushes

27 / 30

. In the spring parking brake system, the brakes are applied by spring pressure and retracted by what?

None of these

Hydraulics

Air pressure

Spring pressure

28 / 30

What can be accomplished by installing a control valve in the cab and a front brake limiting valve on the front axle?

Reduce the braking effort to the front wheels

To improve vehicle mileage

To reduce the speed of the vehicle without braking

None of these

29 / 30

What happens to allow reservoir air pressure to flow to the spring parking brake chambers?

Opening the control valve

Closing the control valse

None of these

Releasing the foot valve

30 / 30

when the brake drum has expanded because of extreme heating, when the brake drum starts to cool and contract, the pressure exerted by the spring parking brake may cause the brake drum to do what?

Stop the vehicle quickly

Crack or warp

Fall off

None of these

Your score is

Air Brake Practice Test 04

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