In the event of an air leak in a parked trailer, what risk does it pose?

A leak in the air system of a parked trailer poses a significant risk that the trailer could roll away. This is primarily because many trailers rely on air brakes, which function by releasing compressed air to maintain their braking capability. If the air supply is compromised, as in the case of an air leak, the brakes can lose their effectiveness, leading to a failure to hold the trailer in place.

This situation creates a dangerous environment where the trailer could roll if it is not properly secured. Other safety measures, such as wheel chocks or engaging the tractor's parking brakes, may also be necessary to prevent movement. While a leak could affect other systems, such as potentially leading to a shift in load or issues with fuel lines in other circumstances, the most immediate and dangerous risk from an air leak specifically relates to the potential movement of the trailer due to compromised braking capabilities.