Air Brakes #2
Air Brakes Endorsement Test | Tennessee 2025 #2 Page 4 of 4
Train for FREE online with our Tennessee 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 TN 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.
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19 . Dollies equipped with ABS are required to have malfunction lamps located where?
On the top
A dolly equipped with an Anti-Lock Braking System (ABS) is required to have a yellow malfunction lamp located on its left side.
20 . The air pressure in a dual air brake system should build from 85 to 100 psi within:
45 seconds.
When inspecting a vehicle with a dual air brake system, you should wait for air pressure to build from 85 to 100 psi in both the primary and secondary systems. This should take about 45 seconds.
21 . Why do you need to drain air tanks regularly?
To remove bad air from the tanks
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. Tanks must be drained regularly to remove this build-up.
22 . Brake linings should be:
Brake linings should not be loose or soaked with oil or grease. They shouldn't be dangerously thin.
23 . Front brake limiting valves were intended to:
Remove uncertainty when applying the brakes.
Some older vehicles with air brakes have front brake limiting valves. These valves were intended to reduce the risk of front wheels skidding. However, research has shown that such devices are unnecessary, so they should be left in the "normal" position.
24 . Air tank drains:
Must remain open while driving.
