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Ohio CDL — Air Brakes practice

Penalties & Licensing

The point system, license suspension, provisional-license rules, insurance requirements, and other licensing basics.

Questions reviewed against the official Ohio driver handbook · July 7, 2026

6 questions · pass with 5 correct. You get instant feedback and an explanation after every answer.

Study questions with answers

6 sample Penalties & Licensing questions with the correct answer, a short explanation, and the official handbook reference. Read through them, then take the quiz above.

  1. 1. How large a crack in a brake drum is allowed before the drum is considered unsafe?

    Correct answer: No more than halfway across the width of the friction surface

    A drum or disc is unsafe once a crack extends more than halfway across the width of its friction surface.

    Source: Ohio CDL Manual — Section 5: Air Brakes

  2. 2. According to the manual, what is the most common brake defect found during roadside inspections?

    Correct answer: Brakes that are out of adjustment

    Out-of-adjustment brakes turn up more often than any other defect at roadside inspections, which is exactly why the slack-adjuster check matters.

    Source: Ohio CDL Manual — Section 5: Air Brakes

  3. 3. What does the manual say about manually adjusting an automatic slack adjuster just to bring it within limits?

    Correct answer: It usually just hides a mechanical problem instead of fixing it

    Manually adjusting an automatic adjuster to force the pushrod stroke within limits generally only masks a mechanical problem rather than fixing it, and it can give a false sense of security.

    Source: Ohio CDL Manual — Section 5: Air Brakes

  4. 4. Air-brake truck tractors built on or after which date are required to have antilock brakes?

    Correct answer: March 1, 1997

    Air-brake truck tractors manufactured on or after March 1, 1997, are required to carry antilock brakes. The certification label shows the build date.

    Source: Ohio CDL Manual — Section 5: Air Brakes

  5. 5. When you pull hard on an s-cam slack adjuster, about how much free movement suggests it needs adjustment?

    Correct answer: More than roughly an inch of play at the push rod connection

    If a slack adjuster shows more than about an inch of play at the point where the push rod connects, it likely needs adjusting. Too much brake slack makes a vehicle very hard to stop.

    Source: Ohio CDL Manual — Section 5: Air Brakes

  6. 6. For other air-brake vehicles such as trucks, buses, trailers, and converter dollies, ABS is required on those built on or after what date?

    Correct answer: March 1, 1998

    Air-brake trucks, buses, trailers, and converter dollies made on or after March 1, 1998, must be equipped with antilock brakes.

    Source: Ohio CDL Manual — Section 5: Air Brakes

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Every Ohio question is written from the official Ohio driver handbook and checked against its current edition. DMV Test Free is a free, independent study resource — not affiliated with any DMV or government agency. About DMV Test Free