Why should you check both the tractor and any converter dolly or trailer air tanks during a multi-unit combination's pre-trip inspection?
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Correct answer to question 113 (Air Brakes): Each unit has its own air storage, and a problem isolated to one unit could otherwise go unnoticed
Why
In a combination with multiple units, each may have its own air tanks and components, so checking each unit separately helps catch a problem that is isolated to just one part of the combination.
Updated: November 2026
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