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

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

2 / 30

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

It retracts

It does not expand

It does expand

Nothing happens

3 / 30

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

None of these

The trailer service brakes

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

The trailer spring brakes

4 / 30

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

They could get stuck

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

They could break

There is no danger

5 / 30

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

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

The brakes no longer grab

6 / 30

Instruction on how to cage is usually found where?

With the vehicle's manual

From a licensed mechanic

On the body of the parking brake chamber

From the carrier

7 / 30

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

The adjustment of the service brakes

The weight and speed of the vehicle

The spring force of the spring brakes that have been installed

The type of spring brakes

8 / 30

The spring parking brake system can also act as what?

Hydraulic brakes

Air-over hydraulic brakes

An emergency brake

Service brakes for the trailers

9 / 30

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

Winding them off

Turning them down

Letting them cool

Turning them up

10 / 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

11 / 30

How many uses does the relay valve have?

Two

Four

One

Three

12 / 30

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

Less than 20%

Less than 60%

Less than 50%

Less than 45%

13 / 30

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

Manually caged

Wrong size

Expanded

Missing

14 / 30

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

The two-way valve

The quick release valve

The one-way valve

The relay valve

15 / 30

How are the brakes caged?

With a valve that releases the spring

With a bolt that runs beside the chamber body

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

With a twist of the release valve

16 / 30

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

All of the above

The vehicle owner

A qualified mechanic or technician

The driver

17 / 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

None of these

To improve vehicle mileage

To reduce the speed of the vehicle without braking

18 / 30

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

The activated position

The forward position

The resting position

The release position

19 / 30

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

Draining the wet tank

Turning off the compressor

Releasing the two-way valve

Blocking the wheels

20 / 30

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

Keep the engine running between 600 and 900 rpm

Stop the engine and leave the transmission in the lowest gear

Park on level ground

Block the wheels

21 / 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

All but fire trucks

Yes

22 / 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

23 / 30

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

The pressure gauge activates

The spring parking brakes will be activated

A warning light activates

Nothing

24 / 30

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

A fan

Nothing

A dust cap

A filter

25 / 30

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

Smooth

Wet

Normal

Rough

26 / 30

The effectiveness of the spring parking brake depends on what?

The size of the spring

The service brake adjustment

The pressure the spring provides

The type of brakes

27 / 30

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

None of these

Air pressure

Spring pressure

Hydraulics

28 / 30

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

Compressing the spring with a caging bolt

Finding out which spring has to be caged

Releasing the spring

Releasing the air pressure

29 / 30

What is another word for when the spring compresses?

Cages

Shrinks

Pushes

Downsizes

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?

None of these

Stop the vehicle quickly

Fall off

Crack or warp

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Air Brake Practice Test 04

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