What is the purpose of the warning signal in an air brake system?

The warning signal in an air brake system serves a critical safety function by alerting the driver of low air pressure. This is important because air brakes rely on compressed air to function properly. If the air pressure drops below a certain level, it indicates that the air brake system may not be able to operate effectively, increasing the risk of brake failure. The warning signal typically activates when the air pressure falls to a predetermined threshold, allowing the driver to take immediate action to address the issue, such as pulling over and inspecting the system or refilling the air tanks. This proactive measure helps ensure the safety of the driver and others on the road by indicating a potential malfunction before it leads to a more serious problem.