At what PSI does the air compressor stop pumping air?

The air compressor in air brake systems is designed to stop pumping air at approximately 125 PSI. This is an important pressure level because it ensures that the air tanks have sufficient air pressure to operate the brakes effectively while preventing over-pressurization, which could lead to damage or malfunction. Once the air pressure reaches this threshold, the governor, a component of the air compressor system, will cut off the air supply to maintain safety and efficiency. Keeping the pressure consistent at around 125 PSI allows the braking system to function optimally, as it ensures that there is enough compressed air ready to engage the brakes when needed.