Montana CDL — Air Brakes Practice Test

The Montana 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.

Montana 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
The manual says the low air pressure warning must come on before tank pressure falls below 55 psi. What alternative figure does it give for older vehicles?
Test 2
25 questions · pass with 20
In the air leakage rate test on the vehicle inspection test, you shut off the engine, release the brakes and press the foot brake all the way down. When does the manual's one-minute count begin?
Test 3
25 questions · pass with 20
During the final air brake check, the compressor does not cut in and cut out the way the manual describes. What danger does the manual see in a governor that is not working properly?
Test 4
25 questions · pass with 20
On an older ABS system, the yellow malfunction lamp is still lit as you pull away from a stop. According to the manual, when might that still be normal?
Test 5
25 questions · pass with 20
A bus has lost its main air pressure and the spring brakes are on. The driver uses the spring-loaded control fed by a separate air tank to release them and move. Why does the manual say to plan that move carefully?
Test 6
25 questions · pass with 20
You have just come down a steep grade and your brakes are very hot. The manual says not to use the parking brakes yet. How does it say to hold the vehicle in the meantime?
Test 7
25 questions · pass with 20
The manual gives two other names for the brake pedal on an air-braked vehicle. Which pair is it?
Test 8
25 questions · pass with 20
It is January and your truck has an alcohol evaporator and manually drained air tanks. A coworker says the evaporator means you can skip draining the tanks. What does the manual say?
Test 9
25 questions · pass with 20
During the final air brake check, the compressor does not cut in and cut out the way the manual describes. What danger does the manual see in a governor that is not working properly?
Test 10
25 questions · pass with 20
A driver makes a habit of manually adjusting his truck's automatic slack adjusters every week. Besides hiding a mechanical problem, what does the manual say this routine is likely to cause?