Air Brake Coach
Brake adjustmentQuestion 58 of 116

What is the best free stroke for a manual slack adjuster?

  1. 2 inches
  2. 1/2 inch (13 mm)
  3. 1/8 inch
  4. 1 inch
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Correct answer: 1/2 inch (13 mm)

The best free stroke is 1/2 inch (13 mm). Adjust again when it reaches 3/4 inch (19 mm).

Source: Air Brake Manual: A Guide for Instructors (Government of Alberta, Alberta Transportation, March/April 2012), Module 8: Foundation brakes, page 79

Practice brake adjustment

Questions last reviewed: 18 October 2026