Air Brake Coach
TrailersQuestion 36 of 116

From which tractor tank does the trailer receive its air?

  1. The tank with the lower pressure
  2. The tank with the higher pressure
  3. Only the secondary tank
  4. The park tank
Show answer

Correct answer: The tank with the higher pressure

The air for the trailer tanks comes from the higher of the two tractor service tanks.

Source: Air Brake Manual: A Guide for Instructors (Government of Alberta, Alberta Transportation, March/April 2012), Module 6: Tractor and trailer circuits, page 62

Practice trailers

Questions last reviewed: 18 October 2026