Kansas 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

With the brakes applied at 90+ psi, the maximum air loss is:

Answer: under 3 psi/min single, under 4 psi/min combination — Applied: under 3 psi/min single, under 4 psi/min combination (combination is always 1 psi looser).

Why should you never press the brake pedal while the spring brakes are on?

Answer: The combined spring and air force can damage the brakes — Combined forces can damage the brakes; build the habit of not doing it.

ABS (antilock braking system):

Answer: Keeps wheels from locking and helps you keep control during hard braking — ABS prevents lockup and helps control; it does not necessarily shorten stopping distance and is an addition to normal brakes.

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: Kansas Department of Revenue, Division of Vehicles

CDL licensing in Kansas is administered by the Kansas Department of Revenue, Division of Vehicles. Fees, scheduling, forms, and the official Kansas CDL manual live on the official site: Kansas DOV — official CDL page (verified 2026-08-09).

Truckcess is not affiliated with or endorsed by the Kansas Department of Revenue, Division of Vehicles. 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 Kansas practice tests

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

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