Air Brake Coach
Spring brakesQuestion 17 of 116

What holds the park control valve (yellow button) in the pushed-in position?

  1. Air pressure
  2. A magnet
  3. The hand valve
  4. The governor
Show answer

Correct answer: Air pressure

The yellow button sits on a spring loaded spool. Air pressure holds the spool in.

Source: Air Brake Manual: A Guide for Instructors (Government of Alberta, Alberta Transportation, March/April 2012), Module 5: Park circuit, page 57

Practice spring brakes

Questions last reviewed: 18 October 2026