Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Manually operated air tank drains must be opened daily to remove this build-up.

Be used to drain the tanks completely.

Only be used when it is wet outside.

Be used to drain the tanks completely.

If you do not take or pass the air brakes test, you will be restricted to operating vehicles without air brakes.

You won’t be permitted to drive a vehicle with air brakes.

Your CDL will include an air brake endorsement marked with an asterisk.

On vehicles with air brakes, a low air pressure warning signal will come on if the pressure in the air tanks falls below 60 psi. On large buses, the signal may activate at 80 to 85 psi.

A warning light should come on.

Lights should flash on the outside of the vehicle.

A message should appear on the control panel.

You should never rely only on warning signals to alert you to an approaching train. Never try to race a train to a crossing. If there are multiple tracks at a crossing, be sure to check all tracks in both directions before starting to cross.

You should not rely only on warning signals.

You will likely be able to outdrive a train.

You should not rely only on warning signals.

You should roll a window down to listen for an approaching train.

You should only worry about the track closest to your vehicle.

FREE CDL Class A Driving Test Online South Carolina 2024 Page 3 of 7

Train for FREE online with our South Carolina class A license test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a SC CDL class A permit in 2024, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that CDL class A requirements may vary from state to state.

To help you pass your CDL exam and become a safer driver, your knowledge of safe commercial driving will be examined, including right-of-way restrictions, railroad and highway crossings, braking and backing tactics, coping with exceptional road and weather situations, and much more. Good luck on the practice exam; take it as many times as you need to feel comfortable with the material, and drive carefully!

Ideal for:

CDL holders who want to add endorsements to their license
First-time SC CDL and CLP applicants
Applicants for CDL renewal in SC

On the actual SC CDL exam:

There are 50 questions
To pass, you must get 40 right answers
80% passing score

Number of Question 50

Passing Score 40

Number of Tests 20

FREE CDL Class A Driving Test Online South Carolina 2024 Page 3 of 7

15 . Air tank drains should:

16 . Mismatched tire sizes are acceptable on the rear axles.

17 . A vehicle equipped with an Anti-Lock Braking System (ABS) uses a ____ light to warn that the system is not working properly.

18 . What happens if you don’t pass the air brakes endorsement test?

19 . What is the average driver’s reaction time?

20 . What should happen if the air pressure in the air brake system tanks falls below 60 psi?

21 . When approaching a railroad crossing:

See the exact questions that will be on the 2024 DMV exam.

Wait, before you go