You're driving a tractor unit fitted with 2 air lines. You want to couple to a trailer that has 3 air-line couplings. How should the air lines be connected?

You're driving a tractor unit fitted with 2 air lines. You want to couple to a trailer that has 3 air-line couplings. How should the air lines be connected?

The trailer auxiliary line should be left unconnected

Correct answer

DVSA explanation

A two-line system consists of the emergency line (red) and the service line (yellow). You need to understand the rules that apply to safe connection of brake systems and mixing two-line and three-line systems.

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