At what air supply pressure level should the low air warning device be activated in a dual air system?

The low air warning device in a dual air brake system is designed to activate when the air supply pressure falls below a critical threshold, ensuring the driver is alerted to a potentially dangerous situation. In a dual air brake system, the low air warning device typically activates at 60 psi. This is crucial for maintaining safe operation of the vehicle, as reduced air pressure can impair braking performance significantly. By having this warning at 60 psi, it provides a timely alert for the driver to take action, such as checking for leaks or reducing speed, thereby enhancing overall safety on the road. It is important for all drivers, especially those operating school buses, to be aware of this pressure level to ensure they can respond effectively to any loss of air pressure in the braking system.