Before driving a truck or bus with a dual-air brake system, what should the pressure in each system be at least?

The pressure in each system of a dual-air brake system should be at least 100 psi before operating a truck or bus. This minimum pressure ensures that the air brake system functions effectively and safely. Air brakes rely on compressed air to apply the brakes, and having sufficient pressure is critical for the brakes to engage promptly and effectively.

If the pressure is below this threshold, the braking system may not function as intended, leading to potentially hazardous situations. Maintaining proper pressure is crucial for the reliability of emergency braking capabilities and overall vehicle control. Therefore, starting with at least 100 psi helps ensure that the brakes will respond in case of an emergency and that drivers have optimal control of their vehicle.