What happens when pressure decreases in the spring brake system?

In a spring brake system, when pressure decreases, the springs are designed to engage the brakes automatically. This is a safety feature intended to bring the vehicle to a stop if the air pressure in the braking system drops below a certain level. The springs are held back by pressurized air; when that pressure decreases, either due to a leak or another malfunction, the springs can push against the brake components, effectively applying the brakes. This ensures that the vehicle does not roll away and helps maintain safety in case of an air pressure loss.

Understanding the function of the spring brake system is crucial for drivers, particularly those operating commercial vehicles, as it emphasizes the importance of maintaining proper air pressure and being aware of system failures.