Skip to content

Inspecting Air Brake Systems

Inspecting Air Brake Systems is a required knowledge area under 49 CFR 383.111(b)(5) (pre-trip) and (b)(6) (en route and post-trip), covering the air brake checks a driver must know how to perform.

Practice Inspecting Air Brake Systems

5 Questions

  1. During a walk-around inspection of an air brake vehicle, a slack adjuster moves more than about one inch when pulled hard by hand where the pushrod attaches. What does this indicate?
  2. During a pre-trip air brake check, with the system fully charged, the engine off, and the parking brake released, what is the maximum acceptable air pressure loss rate?
  3. How does a driver test that the low air pressure warning signal is working correctly during a pre-trip inspection?
  4. During the final pre-trip air brake check, how does a driver confirm the spring brakes will engage automatically at the correct pressure?
  5. After completing the pre-trip air brake checks, what is the last step before putting the vehicle in service?