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

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

Spring pressure

Air pressure

Hydraulics

None of these

2 / 30

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

All of the above

The driver

The vehicle owner

A qualified mechanic or technician

3 / 30

How many uses does the relay valve have?

Two

One

Four

Three

4 / 30

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

Releasing the air pressure

Finding out which spring has to be caged

Releasing the spring

Compressing the spring with a caging bolt

5 / 30

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

Turning off the compressor

Blocking the wheels

Releasing the two-way valve

Draining the wet tank

6 / 30

The effectiveness of the spring parking brake depends on what?

The service brake adjustment

The size of the spring

The type of brakes

The pressure the spring provides

7 / 30

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

They could break

There is no danger

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

They could get stuck

8 / 30

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

Wrong size

Expanded

Manually caged

Missing

9 / 30

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

Less than 45%

Less than 20%

Less than 50%

Less than 60%

10 / 30

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

The quick release valve

The one-way valve

The relay valve

The two-way valve

11 / 30

The spring parking brake system can also act as what?

Service brakes for the trailers

Hydraulic brakes

Air-over 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 activated position

The forward position

13 / 30

How are the brakes caged?

With a bolt that runs beside the chamber body

With a twist of the release valve

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

14 / 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 reduce the speed of the vehicle without braking

To improve vehicle mileage

15 / 30

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

The spring parking brakes will be activated

Nothing

The pressure gauge activates

A warning light activates

16 / 30

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

It does not expand

It does expand

It retracts

Nothing happens

17 / 30

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

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

The brakes no longer grab

There is no longer any smoke coming from the brakes

The brake temperature gauge has a level reading

18 / 30

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

Smooth

Rough

Normal

Wet

19 / 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

20 / 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 type of spring brakes

The weight and speed of the vehicle

21 / 30

What is meant by compounding?

The force applied by the spring brakes and the service brake

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

22 / 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

Fall off

Crack or warp

Stop the vehicle quickly

23 / 30

What is another word for when the spring compresses?

Shrinks

Cages

Downsizes

Pushes

24 / 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

Keep the engine running between 600 and 900 rpm

Block the wheels

25 / 30

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

Letting them cool

Turning them up

Turning them down

Winding them off

26 / 30

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

The trailer spring brakes

None of these

The trailer service brakes

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

27 / 30

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

None of these

Closing the control valse

Opening the control valve

Releasing the foot valve

28 / 30

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

A filter

A fan

A dust cap

Nothing

29 / 30

What is an automatic limiting valve?

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

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

30 / 30

Instruction on how to cage is usually found where?

With the vehicle's manual

On the body of the parking brake chamber

From a licensed mechanic

From the carrier

Your score is

Air Brake Practice Test 04

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