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

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

Less than 20%

Less than 45%

Less than 50%

Less than 60%

2 / 30

What is another word for when the spring compresses?

Shrinks

Downsizes

Pushes

Cages

3 / 30

How are the brakes caged?

With a twist of the release valve

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

With a valve that releases the spring

With a bolt that runs beside the chamber body

4 / 30

Instruction on how to cage is usually found where?

From a licensed mechanic

With the vehicle's manual

From the carrier

On the body of the parking brake chamber

5 / 30

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

To improve vehicle mileage

Reduce the braking effort to the front wheels

None of these

To reduce the speed of the vehicle without braking

6 / 30

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

None of these

The trailer service brakes

The trailer spring brakes

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

7 / 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

They could get stuck

There is no danger

8 / 30

How many uses does the relay valve have?

Three

Two

Four

One

9 / 30

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

Releasing the foot valve

Opening the control valve

None of these

Closing the control valse

10 / 30

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

Smooth

Wet

Rough

Normal

11 / 30

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

It does expand

Nothing happens

It retracts

It does not expand

12 / 30

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

Missing

Manually caged

Expanded

Wrong size

13 / 30

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

All of the above

The driver

A qualified mechanic or technician

The vehicle owner

14 / 30

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

The release position

The resting position

The activated position

The forward position

15 / 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

16 / 30

The spring parking brake system can also act as what?

An emergency brake

Hydraulic brakes

Air-over hydraulic brakes

Service brakes for the trailers

17 / 30

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

Hydraulics

Spring pressure

None of these

Air pressure

18 / 30

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

The one-way valve

The relay valve

The two-way valve

The quick release valve

19 / 30

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

Turning them down

Letting them cool

Turning them up

Winding them off

20 / 30

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

A fan

A dust cap

Nothing

A filter

21 / 30

What is meant by compounding?

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

The force applied when the air pressure is below 35 psi

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

The force applied by the spring brakes and the service brake

22 / 30

What is an automatic limiting valve?

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 0 to 10 psi, depending on how it has been pre-set

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 15 to 20 psi, depending on how it has been pre-set

23 / 30

The effectiveness of the spring parking brake depends on what?

The size of the spring

The type of brakes

The service brake adjustment

The pressure the spring provides

24 / 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?

Crack or warp

None of these

Stop the vehicle quickly

Fall off

25 / 30

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

Nothing

The spring parking brakes will be activated

The pressure gauge activates

A warning light activates

26 / 30

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

The brakes no longer grab

The brake temperature gauge has a level reading

There is no longer any smoke coming from the brakes

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

27 / 30

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

Keep the engine running between 600 and 900 rpm

Park on level ground

Block the wheels

Stop the engine and leave the transmission in the lowest gear

28 / 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

29 / 30

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

All but tandem trailers

Yes

All but fire trucks

30 / 30

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

The spring force of the spring brakes that have been installed

The adjustment of the service brakes

The weight and speed of the vehicle

The type of spring brakes

Your score is

Air Brake Practice Test 04

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