Alabama CDL — Air Brakes Practice Test

The Alabama 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.

Alabama 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 the main cause of brake fade?
Test 2
25 questions · pass with 20
Why should you avoid pressing the brake pedal while the spring brakes are already applied?
Test 3
25 questions · pass with 20
How does the air brake system warn drivers behind you that you are braking?
Test 4
25 questions · pass with 20
In an s-cam drum brake, what happens when air enters the brake chamber?
Test 5
25 questions · pass with 20
On an older vehicle that has one, where should the front brake limiting valve control be kept?
Test 6
25 questions · pass with 20
Your brakes have gotten soaked. How does the manual suggest you dry them out?
Test 7
25 questions · pass with 20
Which type of foundation brake is the most common on vehicles with air brakes?
Test 8
25 questions · pass with 20
How does an air-operated disc brake differ from an s-cam brake?
Test 9
25 questions · pass with 20
What is the purpose of an alcohol evaporator in an air brake system?
Test 10
25 questions · pass with 20
Which type of foundation brake is the most common on vehicles with air brakes?