What happens if the emergency air line breaks or gets pulled while driving?

If the emergency air line breaks or gets pulled while driving, the emergency trailer brakes will engage. In a tractor-trailer combination, the emergency air line is responsible for delivering air pressure to the trailer’s emergency brakes. This system is designed to activate automatically if there's a loss of air pressure, which could occur due to a line break or disconnection. When this happens, the trailer's brakes will immediately engage to prevent it from rolling away or to slow it down. This safeguard helps maintain control of the vehicle and enhances safety by ensuring that the trailer does not become a hazard on the road.

Engaging the emergency brakes is a crucial feature in ensuring that any loss of air in the system does not lead to a more severe situation, such as detachment of the trailer or loss of control of the combined vehicle. This is a vital safety mechanism in preventing accidents and maintaining stability while on the road.