When checking the low air warning, at what pressure must it come on?

The low air warning system is a critical safety feature for commercial vehicles, designed to alert the driver when the air pressure in the system falls below a certain threshold, indicating potential issues with the brake system. The correct pressure at which the low air warning should activate is 60 psi. This specific pressure is set to ensure that the driver is notified well in advance of reaching a critically low air pressure, which could compromise the braking ability of the vehicle.

If the warning light or buzzer does not activate at this pressure, it could lead to a situation where the driver is unaware of low air pressure, potentially risking brake failure. Thus, the 60 psi threshold provides a safety margin, allowing the driver to take corrective action before the air pressure becomes too low for safe operation. This is aligned with safety regulations and the best practices for maintaining the braking efficiency of the vehicle.