When there is a leak in the air bag or associated air suspension pipe, what must be isolated?

Isolating the air suspension system on both bogies of the affected car is crucial when there is a leak in the air bag or associated air suspension pipe. This is because the air suspension system is responsible for maintaining the integrity and performance of the vehicle's suspension. A leak can lead to improper support for the vehicle, potential loss of balance, and compromised ride quality. By isolating the system, technicians can safely address the leak without allowing it to affect other components or the overall stability of the vehicle.

In this context, isolating only the electrical systems of the affected car wouldn't address the immediate concern related to the air suspension. Similarly, addressing all air bags in adjacent cars is unnecessary as the issue is localized to the affected car, and the braking system, while important, is not directly related to the air suspension malfunction and would not resolve the leak issue in question.