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 15 to 20 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 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

2 / 30

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

The resting position

The forward position

The release position

The activated position

3 / 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

4 / 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

5 / 30

Instruction on how to cage is usually found where?

From a licensed mechanic

From the carrier

On the body of the parking brake chamber

With the vehicle's manual

6 / 30

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

Releasing the air pressure

Releasing the spring

Compressing the spring with a caging bolt

Finding out which spring has to be caged

7 / 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

8 / 30

What is another word for when the spring compresses?

Shrinks

Pushes

Cages

Downsizes

9 / 30

The spring parking brake system can also act as what?

Air-over hydraulic brakes

Service brakes for the trailers

An emergency brake

Hydraulic brakes

10 / 30

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

Block the wheels

Keep the engine running between 600 and 900 rpm

Park on level ground

Stop the engine and leave the transmission in the lowest gear

11 / 30

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

Nothing happens

It does expand

It does not expand

It retracts

12 / 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 spring force of the spring brakes that have been installed

The type of spring brakes

The adjustment of the service brakes

13 / 30

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

The trailer service brakes

None of these

The trailer spring brakes

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

14 / 30

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

To reduce the speed of the vehicle without braking

Reduce the braking effort to the front wheels

None of these

To improve vehicle mileage

15 / 30

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

Nothing

A fan

A filter

A dust cap

16 / 30

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

Normal

Wet

Smooth

Rough

17 / 30

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

They could break

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

There is no danger

They could get stuck

18 / 30

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

Releasing the foot valve

Closing the control valse

Opening the control valve

None of these

19 / 30

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

Wrong size

Manually caged

Missing

Expanded

20 / 30

The effectiveness of the spring parking brake depends on what?

The pressure the spring provides

The service brake adjustment

The type of brakes

The size of the spring

21 / 30

What is meant by compounding?

The force applied when the air pressure is below 35 psi

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

22 / 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 60%

Less than 50%

23 / 30

How many uses does the relay valve have?

Two

Four

Three

One

24 / 30

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

Spring pressure

Hydraulics

None of these

Air pressure

25 / 30

How are the brakes caged?

With a valve that releases the spring

With a bolt that runs beside the chamber body

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

26 / 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?

Fall off

Stop the vehicle quickly

None of these

Crack or warp

27 / 30

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

The brakes no longer grab

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

The brake temperature gauge has a level reading

There is no longer any smoke coming from the brakes

28 / 30

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

Turning them up

Letting them cool

Turning them down

Winding them off

29 / 30

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

The relay valve

The two-way valve

The quick release valve

The one-way valve

30 / 30

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

A qualified mechanic or technician

The driver

All of the above

The vehicle owner

Your score is

Air Brake Practice Test 04

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