Virginia CDL — Air Brakes Practice Test

The Virginia 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.

Virginia 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
While a truck is being driven normally, what holds the spring brakes in the released position?
Test 2
25 questions · pass with 20
At about what pressure is the safety relief valve usually set to open?
Test 3
25 questions · pass with 20
How is the air compressor normally driven?
Test 4
25 questions · pass with 20
On a long, steep downgrade, the service brakes should be used in what role?
Test 5
25 questions · pass with 20
What has testing shown about using the front wheel brakes on slippery surfaces?
Test 6
25 questions · pass with 20
What is the purpose of a modulating control valve for the spring brakes?
Test 7
25 questions · pass with 20
The moment the low-pressure warning light and buzzer come on while you are driving, what should you do?
Test 8
25 questions · pass with 20
At roughly what tank pressure does the governor 'cut out' and stop the compressor from pumping more air?
Test 9
25 questions · pass with 20
What is the most common brake problem found during roadside inspections?
Test 10
25 questions · pass with 20
During the final air-brake check, how quickly should pressure build from 85 to 100 psi in a dual air system at operating rpm?