New Jersey CDL — Air Brakes Practice Test

The New Jersey 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.

New Jersey 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 purpose of an alcohol evaporator in some air brake systems?
Test 2
25 questions · pass with 20
What does a supply pressure gauge on an air brake vehicle show the driver?
Test 3
25 questions · pass with 20
Truck tractors with air brakes are required to have antilock brakes (ABS) if built on or after which date?
Test 4
25 questions · pass with 20
What feature is sometimes added to automatic tank drains to keep them working in cold weather?
Test 5
25 questions · pass with 20
You must keep increasing brake application pressure to hold the same speed. What is likely happening, and what should you do?
Test 6
25 questions · pass with 20
On a long, steep downgrade, how should the service brakes be used relative to the engine?
Test 7
25 questions · pass with 20
What happens to the applied braking force as you push the brake (foot) pedal down harder?
Test 8
25 questions · pass with 20
In a drum brake, what actually slows the vehicle and produces heat?
Test 9
25 questions · pass with 20
An air brake setup is really a combination of which braking systems?
Test 10
25 questions · pass with 20
You must keep increasing brake application pressure to hold the same speed. What is likely happening, and what should you do?