Tennessee CDL — Air Brakes Practice Test

The Tennessee CDL — Air Brakes knowledge test has ~25 questions; you need ~20 correct (80%) to pass.

Or take one of 10 full-length practice tests

25 questions · pass with 20 correct. You get instant feedback and an explanation after every answer.

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The full-length test, with feedback and an explanation after every answer.

Tennessee CDL — Air Brakes practice tests

10 full-length practice tests, each with 25 questions and a pass mark of 20, like the real test. You see the answers and explanations after you grade.

Test 1
25 questions · pass with 20
What is a "wig wag" low air pressure warning device?
Test 2
25 questions · pass with 20
What does a supply pressure gauge tell the driver?
Test 3
25 questions · pass with 20
What does the service brake system do?
Test 4
25 questions · pass with 20
At roughly what pressure does the governor cut out and stop the compressor from pumping?
Test 5
25 questions · pass with 20
What is the main job of an antilock braking system (ABS)?
Test 6
25 questions · pass with 20
What does the manual say about front wheel braking under slippery conditions?
Test 7
25 questions · pass with 20
Why is it important to drain the water that collects in the air tanks?
Test 8
25 questions · pass with 20
Why should you avoid pressing the brake pedal while the spring brakes are already applied?
Test 9
25 questions · pass with 20
When should you NOT use the parking brakes to hold the vehicle?
Test 10
25 questions · pass with 20
With the engine off and the brakes released, what is the maximum acceptable air leakage for a combination vehicle over one minute?