If the low air pressure warning signal comes on while you are operating a vehicle with air brakes, you should stop and safely park the vehicle as soon as possible. It is essential that you are able to stop safely while you still have some braking power remaining.

Test the brakes while driving, but continue driving if nothing seems wrong.

Drive with the hazard lights activated.

If brakes are overused, they can become too hot. This overheating causes them to fade, making them less effective at slowing the vehicle.

Brakes being exposed to sunlight.

Brakes being exposed to moisture.

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.

Opened to drain the tanks after each day.

An air compressor governor will stop the compressor from pumping air once the air tanks are at an air pressure level around 125 psi. This air pressure level is referred to as the "cut-out" level.

Stop the compressor from pumping air.

Begin pumping air into the tanks.

In an air brake system, the air storage tanks hold compressed air to be used by the brakes. The number and size of air tanks varies among vehicles.

Hold compressed air for the brakes.

Should be drained of excess air after every trip.

All trucks, truck tractors, and buses must be equipped with emergency brakes and parking brakes.

Are not required on vehicles with air brakes.

Air Brakes Endorsement Test | Iowa 2024 #2 Page 4 of 4

Train for FREE online with our Iowa 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 IA Class A/Class B driver license 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 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 | Iowa 2024 #2 Page 4 of 4

19 . If the low air pressure warning signal comes on in a vehicle with air brakes, the driver should:

20 . Brake fade is a result of:

21 . Manual air tank drains should be:

22 . Once the air tanks are at an air pressure level of 125 psi, the air compressor governor will:

23 . A slack adjuster should move no more than ____ from where it is attached to the push rod.

24 . Air storage tanks:

25 . Emergency brakes:

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

Wait, before you go