What action is required on a T car if a MR leak is detected?

When a MR (Main Reservoir) leak is detected on a T car, the appropriate action is to blank the pipe if possible or declare it disabled. This is essential for several reasons related to safety and operational integrity.

Blanking the pipe effectively isolates the leak, preventing further loss of air and maintaining the functionality of the air brake systems that rely on a stable air pressure supply. Declaring the car disabled ensures that it is removed from service until the issue can be resolved, maintaining overall safety in rail operations. This action prioritizes safety protocols by preventing the operating risks that could arise from traveling with a compromised air system.

Other options such as replacing all affected air bags or reporting the issue to passenger service do not directly address the immediate hazard presented by the leak. Furthermore, increasing speed to reach the nearest station could exacerbate the problem, leading to potential failures or accidents. Therefore, immediate action to contain the leak is critical to ensure the safe operation of the train.