AIR BRAKES TEST – 02

The Commercial Driver License Air Brakes Practice Test is designed to help you prepare for the state test. With this practice test your knowledge will be challenged. These practice test questions are designed to see where you stand before you take your CDL. These tests will let you know what areas you will need to improve on. Although these practice tests will prepare you for your state Commercial Driver License it is important to refer to your book. Please refer to your state Commercial Drivers License study guide for answers that may differ from the practice test. In the event that your state booklet has a different answer then your practice test please refer to your state booklet for the correct answer.

Air Brake Test 02

1 / 30

Before you check the slack adjusters on S-cam brakes, you should...?

Chock the wheels

Turn on the engine

Wedge the foot brake

Apply the parking brake

2 / 30

If air hoses connected to brake chambers are cut or worn, they should be...?

Any of these depending on circumstances

Replaced

Taped up

Noted on your report

3 / 30

The most common flaw found in roadside inspections of air brake systems is...?

Worn brake shoes

Worn brake linings

Broken springs

Out of adjustment brakes

4 / 30

You have fully-charged air system (125). After turning off the engine and releasing the service brake, what is the maximum leakage rates per minute for both single and combination vehicles?

5 psi for single, 7 psi for combination

2 psi for single, 3 psi for combination

4 psi for single, 5 psi for combination

1 psi for single, 2 psi for combination

5 / 30

The air loss rate for a straight truck or bus with engine off and brakes on, should not be more than:

1 p.s.i. in 60 seconds

2 p.s.i. in 45 seconds

5 p.s.i. in 30 seconds

4 p.s.i. in 45 seconds

6 / 30

Vehicles will have automatic slack adjusters if they were built since...?

1997

1994

2000

1991

7 / 30

If on an automatic slack adjuster the push rod stroke exceeds the legal brake adjustment limit, it indicates that...?

Any of these might be the problem

The adjuster is broken

The adjuster was improperly installed

There is a problem with the brake components

8 / 30

If your vehicle has ABS, your stopping distance compared to a non-ABS vehicle will be reduced by...?

10%

20%

30%

9 / 30

Brake drums or discs must not have cracks which are longer than what proportion of the width of the friction area?

60%

40%

30%

50%

10 / 30

Before driving a vehicle with a dual air system you should allow the air compressor to build up a minimum of what pressure in both systems?

90 psi

80 psi

70 psi

100 psi

11 / 30

If you find an automatic adjuster is outside the brake pushrod stroke legal limit, you should...?

Adjust it yourself

Ask a mechanic to adjust it

Ask a mechanic to overhaul the brakes

Ignore it

12 / 30

In a dual air brake system, the 'primary' system will usually operate the regular brakes on...?

The rear axle or axles

Both axles

The front axle

Any of these

13 / 30

The proper method of braking while going down long of steep curves after selecting the proper gear is to brake until your speed drops to _____mph below the safe speed then release your brakes?

14 / 30

On tractors, trucks and buses, the ABS malfunction lamp will be found...?

On the gear lever

On the steering wheel

On the instrument panel

Behind the front bumper

15 / 30

Under ideal conditions, a truck with air brakes going 55 miles per hour requires stopping distance of:

More than 600 feet

More than 500 feet

More than 300 feet

More than 400 feet

16 / 30

The best way to find out if a vehicle built before ABS was a mandatory requirement is equipped with the system is to...?

Test the brakes at speed

Look at the rear of the vehicle

Look under the vehicle

Look on top of the vehicle

17 / 30

A dual air brake system has how many separate air brake systems?

Two

One

Four

Three

18 / 30

In dual air brake systems, which of these will be individual to each system?

Air hoses

All of them

Air tanks

Air lines

19 / 30

On older ABS systems, the malfunction lamp may not go out until you exceed...?

5 mph

15 mph

20 mph

10 mph

20 / 30

If the pressure in a dual air system drops below 60 psi for one system but stays normal for another, you should...?

Have it fixed at the next routine maintenance

Have it fixed the next time the vehicle is not being used

Stop immediately and have it fixed

Continue driving as normal

21 / 30

You should test the low pressure warning signal with...?

Engine off and electrical system on

Engine on and electrical system off

Engine off and electrical system off

Engine on and electrical system on

22 / 30

When you pull hard on a slack adjuster, it probably needs adjustment if it moves more than...?

3 inches

2 inches

Half an inch

1 inch

23 / 30

Air brake vehicles other than truck tractors will definitely have ABS if built after March 1...?

1996

1998

1999

2000

24 / 30

In a dual air brake system the 'secondary' system will usually operate the regular brakes on...?

Both axles

The front axle

The rear axle or axles

Any of these

25 / 30

A trailer with ABS will have a malfunction lamp...?

In any of these places

On the right side

At the rear

On the left side

26 / 30

Which of these applies to vehicles with automatic slack adjusters?

They don't need checking at all

Any of these depending on age of vehicle

They can be checked less often

They must be checked just as often

27 / 30

What is another name for 'squeeze' braking?

Emergency braking

Spring braking

Controlled braking

Foundation braking

28 / 30

If the low-pressure warning signal does not work properly, what should you do?

Ignore it

Not drive until it is fixed

Note it on your report

Schedule it for fixing at the next routine maintenance

29 / 30

During the engine compartment check part of your inspection procedure on an air brake equipped vehicle you should check...?

The springs

The air hoses

The oil levels

The air compressor drive belt

30 / 30

If you fan the brake pedal to reduce tank pressure with the engine off, the spring brakes should activate when the air pressure drops to...?

30 – 55 psi

50 – 75 psi

20 – 45 psi

40 – 65 psi

Your score is

Air Brakes Test

Getting a commercial driver’s license (CDL) is no different from getting your regular driver’s license. However, it is important to understand that a CDL has restrictions and one of them is the air brake restriction. This means that you cannot drive a vehicle equipped with this type of brakes unless you have passed a written air brakes test and have your skills tested on the road with a vehicle equipped with these brakes. Here is all you need to know about getting air brakes endorsement on your commercial driver’s license.

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.