Delaware CDL — Air Brakes Practice Test

The Delaware 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.

Delaware 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
Each time you let up on the brake pedal, what happens to the air in the system?
Test 2
25 questions · pass with 20
Your ABS stops working partway through a trip. You still have your regular brakes and keep driving normally. What else does the manual tell you to do?
Test 3
25 questions · pass with 20
Step 2 of the inspection adds one air brake item when the compressor runs off a belt. What do you look at?
Test 4
25 questions · pass with 20
On your walk-around, you look over the air hoses that run to the brake chambers. What are you checking for?
Test 5
25 questions · pass with 20
Front brake limiting valves on older trucks were meant to make front-wheel skids less likely on slick roads. What does the manual say they actually do?
Test 6
25 questions · pass with 20
You are about to troubleshoot a brake adjustment problem on a vehicle with automatic slack adjusters. What does the manual say to consult first?
Test 7
25 questions · pass with 20
Where in an air brake system is the safety relief valve installed?
Test 8
25 questions · pass with 20
Which of these is NOT one of the four parts of the air brake check on Delaware's CDL vehicle inspection test?
Test 9
25 questions · pass with 20
Your combination vehicle has ABS on just one axle. What does the manual say about that?
Test 10
25 questions · pass with 20
In stab braking, you let off the brakes when the wheels lock. How long can it take before the wheels are rolling again?