Texas Air Brakes Knowledge Test CDL Practice Test
Practice with real TX Air Brakes exam questions and detailed explanations. Rated 4.8 stars by 1,000+ drivers.
Written by CDL holders and exam prep experts · Updated April 2026
Free Questions
10
Passing Score
80%
Time Limit
90 minutes
Prerequisites
General Knowledge test must be completed first
What is the Air Brakes Knowledge Test Test?
The Air Brakes knowledge test is required for commercial vehicles equipped with air brake systems. Passing this test demonstrates your knowledge of air brake operation, inspection procedures, and safety protocols, and removes the 'L' restriction from your CDL.
Knowledge test to remove 'L' restriction (no air brakes) from CDL
Topic Breakdown
Air Brake System Components
~8 questions
- Compressor and reservoir systems
- Brake chambers and slack adjusters
- Air lines and fittings
Inspection and Testing
~7 questions
- Pre-trip inspection procedures
- Air pressure tests
- Brake adjustment checks
Safe Driving Practices
~6 questions
- Proper braking techniques
- Following distance requirements
- Downhill braking procedures
Emergency Procedures
~4 questions
- Air pressure loss procedures
- Emergency braking systems
- Brake failure protocols
Free Practice Questions
10 questionsQuestion 1 of 10
To check the free play of manual slack adjusters of S-cam brakes, you should park on:
Browse Texas Air Brakes Questions
- 1. To check the free play of manual slack adjusters of S-cam brakes, you should park on:
- 2. Stab braking:
- 3. Repeatedly partially increasing and pressing the brake pedal may result in:
- 4. Why drain water from compressed air tanks?
- 5. Which braking technique may be used to stop quickly when you do not have ABS?
- 6. A slack adjuster free play needs to be adjusted if it is more than about ____ when you pull hard on it.
- 7. Parking or emergency brakes of trucks and buses can be legally held on by ____ pressure.
- 8. Which procedure is used for the spring brake test?
- 9. The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure drops below ____ psi.
- 10. The spring brakes of a tractor-trailer will activate once air pressure drops to approximately:
Study Tips for Texas
- 1Understand the air brake system components thoroughly
- 2Practice air pressure testing procedures
- 3Memorize safe following distances
- 4Know emergency braking procedures
- 5Review Texas air brake regulations and inspection requirements
Texas CDL Information
Age Requirements
Intrastate: 18+ · Interstate: 21+
CDL Renewal
Every 4 years
ELDT Required
Yes — ELDT (Entry-Level Driver Training) from FMCSA-registered provider required since February 7, 2022
Texas DPS
Official CDL Portal →Career Opportunities
Frequently Asked Questions
If you plan to drive a commercial vehicle equipped with air brakes, you must pass the air brakes knowledge test to remove the 'L' restriction from your CDL.
Air Brakes Study Resources
Be Ready for Your Texas Air Brakes Test
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