Compressed air in an air brake system usually has a certain amount of water and oil in it. This can harm the system if allowed to accumulate. Air tanks have drain valves to aid in removing water and oil from the compressed air.

Are helpful to remove water and oil from the air tanks.

Should not be used in cold weather.

Are helpful to remove water and oil from the air tanks.

Are used to move air to the brakes.

In an air brake system, the air compressor pumps air into the air storage tanks. The air compressor is controlled by the air compressor governor.

It pumps air into the air storage tanks.

It moves air to the back of the truck.

In a vehicle with dual parking control valves, there is a separate air tank that can be used to temporarily release the spring brakes if they have been activated due to low air pressure. Pushing in the proper control will release the spring brakes for a short period of time, allowing the driver to move the vehicle in an emergency.

To temporarily release the spring brakes.

To make the air brakes work more effectively.

To temporarily release the spring brakes.

To charge the brakes on the rear trailer.

In an air brake system, the air tanks must be periodically drained to remove accumulations of water and compressor oil. If water is not removed, it could freeze in cold weather and cause brake failure.

Water accumulations freezing and causing brake failure.

Too much air collecting in the tanks.

Air Brakes Endorsement Test | Ohio 2025 #2 Page 3 of 4

Train for FREE online with our Ohio CDL air brake 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 OH Class A/Class B driver license in 2025, 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 the requirements for CDL may vary from state to state.

Number of Question 25

Passing Score 20

Number of Tests 20

Air Brakes Endorsement Test | Ohio 2025 #2 Page 3 of 4

13 . Air tank drains:

14 . What does an air compressor do in an air brake system?

15 . In a vehicle with dual parking control valves, a separate air tank can be used:

16 . Failing to drain air tanks could result in:

17 . Before driving a vehicle with air brakes, you should ensure that the ____ come on automatically when air pressure falls below 45 psi.

18 . What kind of brakes do most newer heavy-duty trucks use?

See the exact questions that will be on the 2025 DMV exam.

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