Air Brake Coach
InspectionQuestion 78 of 116

At what engine speed do you run the engine for the supply circuit test?

  1. Idle at 600 RPM
  2. Full throttle
  3. A fast idle of about 1200 RPM
  4. 1800 RPM
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Correct answer: A fast idle of about 1200 RPM

The form says to start the engine and run it at a fast idle around 1200 RPM.

Source: Air Brake Manual: A Guide for Instructors (Government of Alberta, Alberta Transportation, March/April 2012), Air Brake Practical Test (DPLS0003): Supply circuit, page 123

Practice inspection

Questions last reviewed: 18 October 2026