Air Brake Coach
InspectionQuestion 72 of 116

At what pressure must the low air pressure warning come on during the pre-trip?

  1. By 20 PSI
  2. By 90 PSI
  3. By 60 PSI
  4. By 120 PSI
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Correct answer: By 60 PSI

The practical test form says to confirm the warning comes on by 60 PSI (414 kPa).

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

Practice inspection

Questions last reviewed: 18 October 2026