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

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.

Category: Braking Systems

References: The Official DVSA Guide to Driving Goods Vehicles: Section 2