CDL AIR BRAKES PRACTICE TEST – 01

We know that taking the air brakes test as part of your CDL permit can cause anxiety in even the most confident driver. That is why we designed this free CDL air brakes practice test so that you can practice and get an idea of what types of questions will be asked on the actual test at the DMV. We encourage you to take it as many times as you would like or until you get a perfect score. We hope that this practice test proves helpful as you study for your exam. Please visit us again and take all of our practice exams as often as you would like.

Air Brake Test 01

1 / 30

On large buses, it is common for low-pressure warning devices to activate at around...?

70 – 75 psi

65 – 70 psi

80 – 85 PSI

90 – 95 psi

2 / 30

Many vehicles have automatic front wheel limiting valves, which will reduce air to the front brakes unless they are applied with a pressure of greater than...?

40 psi

70 psi

50 psi

60 psi

3 / 30

When air is pumped into a brake chamber, what is the first thing that happens?

The slack adjuster moves

The brake shoes are forced apart

The rod is pushed out

The brake camshaft twists

4 / 30

Air brake systems are three braking systems combined. They are:

Service, Parking, Foundation

Parking, Foundation, Controlled braking

Service, Parking, Emergency

Slack adjuster, Parking, Emergency

5 / 30

The stoplights on an air brake system are activated by...?

Speed sensors

Air pressure

Brake temperature sensors

The driver

6 / 30

Safety relief valves on the first tanks are usually set to open at...?

170 psi

140 psi

150 psi

160 psi

7 / 30

Brakes can stop working if...?

They get too cold

The pedal is pressed too hard

They get too hot

They are at high altitude

8 / 30

The resistance you feel when you push the brake pedal down comes from...?

The resistance of the road surface

Air pressure

A spring and air pressure

A spring

9 / 30

An air compressor governor will resume pumping air to the tanks when tank pressure falls below around...?

100 psi

80 psi

90 psi

110 psi

10 / 30

In a wedge brake system, a push rod pushes a wedge directly...?

Against the tire

Between the brake shoes

Onto the rim of the wheel

Against the drum

11 / 30

The most common sort of emergency and parking brake on large vehicles is...?

Springs and secondary air

Springs

Secondary air

None of these

12 / 30

The air compressor should stop pumping at about ____ P.S.I.

125

100

13 / 30

The application pressure gauge shows...?

The pressure in the air tanks

The tire pressure

The pressure applied to the brakes

The pressure in the compressor

14 / 30

The brake system that applies the use of the brakes when the driver uses the brake pedal is the ______ brake system?

Service

Controlled

Emergency

Parking

15 / 30

Drum brakes work by pressing brake shoes and linings against...?

The wheel rim

The axle

The tire

A drum

16 / 30

Emergency brakes and parking brakes on all large vehicles must be operated by...?

Mechanical force

Wind resistance

Air pressure

Oil

17 / 30

If application pressure increases without a decrease in speed, you need to...?

Slow down and choose a higher gear

Remain in the same gear but speed up

Slow down and choose a lower gear

Remain in the same gear but slow down

18 / 30

An air pressure system is fully charged at _____ P.S.I.?

100

125

19 / 30

You should drain air tanks at the end of...?

Every day

Every week

Every 1000 mile plus trip

Every month

20 / 30

If the spring brakes are on you should push the brake pedal.

Always

Never

21 / 30

Foundation brakes can be found on...?

The front wheels

The rear wheels

Every wheel

The middle wheels

22 / 30

Air tanks should be drained to clear them of...?

Excess air

Water

Oil and water

Oil

23 / 30

Pumping the brake pedal up and down unnecessarily can result in...?

Any of these

Water entering the tanks

High air pressure

Low air pressure

24 / 30

Which of these brake systems uses a 'power screw'?

Disc brakes

S-cam brakes

Wedge brakes

All of these systems

25 / 30

When the low air pressure warning light or buzzer comes on, you should...?

Monitor the situation

Wait for the spring brakes to deploy automatically

Stop immediately

Any of these depending on circumstances

26 / 30

Spring brakes are usually fully activated when the air pressure is between...?

20 – 30 psi

30 – 40 psi

0 – 10 psi

10 – 20 psi

27 / 30

Supply pressure gauges on an air brake system tell you...?

The pressure in the compressor

The pressure in the air tanks

The pressure applied to the brakes

The external air pressure

28 / 30

The low air pressure warning signal on an air brake system must come on before the air pressure falls below...?

60 psi

70 psi

50 PSI

40 psi

29 / 30

On vehicles made before 1975, if the front brake limiting valve control is switched to 'slippery' the air pressure to the front brakes will be cut by...?

20%

50%

40%

30%

30 / 30

Air compressor governors are programmed to cut out when air pressure reaches around...?

125 psi

145 psi

135 psi

115 psi

Your score is

Study CDL Air Brakes Practice Test and Applying for the for the Air Brake endorsement

When applying for the Air Brake endorsement taking a written test, the first thing to do is to verify that you meet the requirements for sitting for the written test. You should then verify the amount of fees you are required to pay as you apply.

You should then fill up the air brake endorsement written test application then turn it in. Schedule an appointment for the skills test. This should only be done after you are comfortable and ready for the test. To be ready, make sure you read the CDL handbooks and take this CDL air brakes practice test to find out if you’re ready for the actual written test.

There are three types of CDL classes that determine the type of vehicle you may drive and how much you may tow. A Class A CDL class allows you to operate a vehicle with a GCWR of 26,001 if the vehicle you tow weighs more than 10,000 and a Class B CDL allows you to operate a vehicle with a GVWR of 26,001 or more pounds or operate any vehicle towing another vehicle that weighs less than 10,000 GVWR. With a Class C CDL, you can operate a Class C vehicle that transports hazardous materials.

Eligibility for CDL Air Brake Test

You will, of course, need to have some driving skills before you seat for a CDL air brake test. Then you will need to have an understanding of the braking supply system. In this case, you need to understand that air is pumped into the braking supply system from the atmosphere. You should know how it passes through filters and dries before it is stored in the main reservoir.

To be eligible for the CDL air brake test, you should understand how air is maintained and the constant pressure to drive under. The constant pressure is normally around 125 psi. Maintenance will be needed for the pressure mounts at 150 psi.

You should have an understanding of the parking brake. This is a safety feature of an air brake system. This is a spring-actuated brake that prevents the vehicle from moving. It is normally engaged by default. The air that mounts in the braking system pulls the spring open and disengages the brake.

To be eligible for the air brake endorsement on your CDL, you must have the basic knowledge of other parts of a truck that power the brakes other than just the compressed air. It is important to understand that pedals and the gearbox system use compressed air to amplify and assist the input of the driver.

The cost of a CDL air brake endorsement
normally, there is a fee charged by the state Department of Public Safety and Correctional Services for the HAZMAT background record check. The TSA processing fee and the state and federal background checks have been reduced to $88.75. It is also important to understand that there is a fee charged for correcting a CDL or adding an endorsement. However, no charges will apply if you were required to obtain a commercial learner’s permit.