ABS and Air Brake Emergencies - ONLINE CDL SCHOOL

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ABS and Air Brake Emergencies

Build confidence with 10 original questions about ABS and Air Brake Emergencies. Review your answers and explanations after finishing.

Supplemental study practice. This is not a government licensing exam or ELDT certification, and does not replace hands-on training. Follow your state’s current handbook.

1 / 10

You are driving a vehicle with ABS and the system fails. How does this affect your normal braking ability?

The parking brake will not function.

The air compressor will stop working.

Normal brakes still work, but ABS will not prevent wheel lockup.

The service brakes will not apply at all.

2 / 10

While driving, you notice your air pressure gauge stops rising even though the engine is running. What should you suspect?

The brake drums are overheated.

The alcohol evaporator is empty.

The air compressor governor has reached cut-out pressure.

The spring brakes have engaged.

3 / 10

You are driving a truck with air brakes and notice the yellow ABS malfunction lamp stays on after you start the engine. What does this indicate?

The brake linings are worn out.

The parking brake is engaged.

The air pressure is too low for safe operation.

There may be a problem with the ABS system at one or more wheels.

4 / 10

You are inspecting a vehicle with air brakes and notice the ABS malfunction lamp stays on while driving. What should you do?

Drive carefully and have the ABS system serviced soon.

Ignore the light if the brakes feel normal.

Stop immediately and call for a tow.

Release the parking brake and continue driving as usual.

5 / 10

After starting your vehicle, the ABS warning light comes on and then quickly goes out. What does this mean?

The parking brake is not set.

There is a problem with the brake linings.

The ABS system has passed its bulb check and is functioning normally.

The air pressure is below 55 psi.

6 / 10

You are driving a truck with ABS and must make a quick stop on a wet road. What is the main benefit of ABS in this situation?

It automatically applies the parking brake.

It helps you keep control of the vehicle during hard braking.

It increases the braking power of the spring brakes.

It shortens your total stopping distance.

7 / 10

When checking for ABS on a trailer manufactured before March 1, 1998, what should you look for under the vehicle?

A modulating control valve

A yellow diamond-shaped control knob

A manual air tank drain cable

Electronic control unit and wheel speed sensor wires

8 / 10

You are performing a pre-trip inspection and want to verify if your truck is equipped with ABS. Where should you check for the ABS malfunction lamp?

Next to the fuel gauge

On the air tank

On the instrument panel

On the right rear corner of the cab

9 / 10

You are inspecting a trailer and see a yellow ABS malfunction lamp on the left rear corner. What does this lamp indicate?

It warns of low air pressure in the main tanks.

It shows the status of the trailer's ABS system.

It signals the parking brake is applied.

It indicates the trailer lights are on.

10 / 10

You are driving a bus built after March 1, 1998. What braking system must it be equipped with?

Disc brakes only

Hydraulic brakes only

Manual drum brakes

Antilock Braking System (ABS)

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About the ABS and Air Brake Emergencies practice quiz

This practice quiz focuses on ABS and Air Brake Emergencies, listed under CDL Practice — Air Brakes. Use it to check what you understand, spot topics to revisit, and connect the material to safe, informed decisions on the road.

Before you begin

Keep your current CDL manual or course notes nearby. Read each prompt carefully and think through why an answer fits, especially when a question describes a vehicle, road, or workplace situation. Licensing rules and procedures can vary, so confirm requirements with current official materials for your state.

After you finish

Review any explanations shown with your results. Note unfamiliar terms or missed concepts, then revisit your manual or course notes before trying again. Use your score to guide study; understanding why an answer is correct matters more than the number alone.

Study note: These quizzes are independent study practice. They are not state licensing exams, official government materials, or ELDT certification, and they do not replace required training.

Explore CDL Tests to find more practice by subject.