Arkansas Air Brakes Practice Test

Required if the vehicle you'll drive has air brakes — which in practice means nearly every combination vehicle and most straight trucks. The test covers the parts of an air-brake system (compressor, governor, tanks, valves), the specific pressures where things happen (cut-in, cut-out, low-air warning, spring-brake pop-out), and the inspection sequence for leaks and warning devices. Fail this knowledge test or take the skills test in a vehicle without air brakes, and your license carries an air-brake restriction that keeps you out of most trucking jobs.

Who needs it: Anyone who'll drive a vehicle with air brakes. Skipping it puts an L or Z restriction on the license.

Sample practice questions

Why must air tanks be drained?

Answer: To remove water and oil that can damage the system and freeze — Compressed air carries water and oil; water can freeze in cold weather and cause brake failure.

The most common type of foundation brake is the:

Answer: S-cam drum brake — S-cam drum brakes are the most common; wedge and disc are less common.

At about what pressure does the governor stop the compressor from pumping (cut-out)?

Answer: 125 psi — Cut-out is about 125 psi. Cut-in is about 100 psi; 150 psi is the safety valve; 60 psi is the low-air warning.

Common mistakes on the Air Brakes test

  • Mixing up the pressure numbers — cut-out (~125 psi), cut-in (~100 psi), low-air warning (~60 psi) are all tested
  • Confusing spring brakes (parking/emergency) with service brakes — which system does what, and when
  • Forgetting the air-leak rate limits for the applied and released tests during inspection
  • Assuming ABS changes how you brake — the test wants normal braking with ABS, not pumping

Studying with the full Truckcess course does double duty: the theory counts toward the federal ELDT requirement (Truckcess is listed on the FMCSA Training Provider Registry).

Official source: Arkansas Department of Finance and Administration

CDL licensing in Arkansas is administered by the Arkansas Department of Finance and Administration. Fees, scheduling, forms, and the official Arkansas CDL manual live on the official site: Arkansas DFA — official CDL page (verified 2026-08-09).

Truckcess is not affiliated with or endorsed by the Arkansas Department of Finance and Administration. Our practice tests cover the federal CDL knowledge standards (49 CFR Part 383) that every state exam is built on; exact question counts, fees, and procedures vary by state and change over time — the official site is always the authority.

More Arkansas practice tests

Full prep courses are one-time from $59 with 12 months of access — mytruckcess.com/cdl.

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