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

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

None of these

Crack or warp

Fall off

2 / 30

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

A dust cap

A filter

A fan

Nothing

3 / 30

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

The spring parking brakes will be activated

A warning light activates

The pressure gauge activates

Nothing

4 / 30

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

The relay valve

The one-way valve

The quick release valve

The two-way valve

5 / 30

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

It does expand

It retracts

It does not expand

Nothing happens

6 / 30

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

Letting them cool

Winding them off

Turning them up

Turning them down

7 / 30

What is an automatic limiting valve?

It will hold off brake application to the front wheels from 15 to 20 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 35 to 40 psi, depending on how it has been pre-set

8 / 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

There is no danger

They could break

9 / 30

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

Releasing the spring

Releasing the air pressure

Compressing the spring with a caging bolt

Finding out which spring has to be caged

10 / 30

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

Less than 50%

Less than 60%

Less than 20%

Less than 45%

11 / 30

The spring parking brake system can also act as what?

Service brakes for the trailers

Air-over hydraulic brakes

Hydraulic brakes

An emergency brake

12 / 30

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

The release position

The resting position

The forward position

The activated position

13 / 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

14 / 30

How many uses does the relay valve have?

One

Two

Three

Four

15 / 30

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

Turning off the compressor

Releasing the two-way valve

Draining the wet tank

Blocking the wheels

16 / 30

How are the brakes caged?

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

With a bolt that runs beside the chamber body

With a valve that releases the spring

With a twist of the release valve

17 / 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

18 / 30

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

Hydraulics

Air pressure

Spring pressure

None of these

19 / 30

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

Park on level ground

Stop the engine and leave the transmission in the lowest gear

Block the wheels

Keep the engine running between 600 and 900 rpm

20 / 30

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

Smooth

Rough

Normal

Wet

21 / 30

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

The brake temperature gauge has a level reading

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

There is no longer any smoke coming from the brakes

The brakes no longer grab

22 / 30

What is meant by compounding?

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

The force applied by the spring brakes and the service brake

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

23 / 30

Instruction on how to cage is usually found where?

From a licensed mechanic

With the vehicle's manual

On the body of the parking brake chamber

From the carrier

24 / 30

What is another word for when the spring compresses?

Shrinks

Cages

Pushes

Downsizes

25 / 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

To reduce the speed of the vehicle without braking

None of these

Reduce the braking effort to the front wheels

26 / 30

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

None of these

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

The trailer spring brakes

The trailer service brakes

27 / 30

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

The vehicle owner

A qualified mechanic or technician

The driver

All of the above

28 / 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

29 / 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 type of spring brakes

The adjustment of the service brakes

The spring force of the spring brakes that have been installed

30 / 30

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

Expanded

Missing

Manually caged

Wrong size

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Air Brake Practice Test 04

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