Air Brake Coach
InspectionQuestion 80 of 116

What is the most air loss allowed for a power unit in the 2 minute leak check?

  1. 4 PSI (28 kPa)
  2. 1 PSI
  3. 10 PSI
  4. 20 PSI
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Correct answer: 4 PSI (28 kPa)

The maximum loss is 4 PSI (28 kPa) for the power unit. Each trailer adds 2 PSI (14 kPa).

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

Practice inspection

Questions last reviewed: 18 October 2026