Texas CDL — Air Brakes Practice Test
The Texas 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.
Choose your level
The full-length test, with feedback and an explanation after every answer.
Study offline
Texas Practice Test Pack — 2026 Printable Edition
$4.99 · One-time purchase. Instant download.
Our own printable edition — nobody paid us to show it to you, and everything in it is free to read here too.
Texas 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
Unlike hydraulic brakes, air brakes have brake lag. About how long does it take air to flow through the lines and work the brakes after you press the pedal?
- Test 2
25 questions · pass with 20
By law, when must the low air pressure warning signal in an air-braked vehicle activate?
- Test 3
25 questions · pass with 20
The low air pressure warning comes on while you are driving. What is the correct response?
- Test 4
25 questions · pass with 20
Why is it a bad habit to press and release the brake pedal over and over when you don't need to?
- Test 5
25 questions · pass with 20
Some air tanks with automatic drain valves also have electric heating devices. What are the heaters for?
- Test 6
25 questions · pass with 20
In Texas, you take the CDL skills test in a truck that is not equipped with air brakes. What happens to your license?
- Test 7
25 questions · pass with 20
You are performing the static leakage test on a single vehicle: engine off, fully charged system, foot off the brake, parking brake released, and you time the pressure drop. What is the most the pressure may fall?
- Test 8
25 questions · pass with 20
On newer air-braked vehicles the parking brake control is a yellow, diamond-shaped knob. On older vehicles, what might it look like instead?
- Test 9
25 questions · pass with 20
Which list correctly names all the parts of total stopping distance for a vehicle with air brakes?
- Test 10
25 questions · pass with 20
What job does an alcohol evaporator perform in some air brake systems?