How fast should air pressure build from 85 to 100 psi?

The correct answer indicates that air pressure should build from 85 to 100 psi within 45 seconds, which corresponds to standard practices in fire apparatus operation. This timing is crucial because it ensures that the air brake system of the vehicle is functioning properly and that the driver/operator can rely on the brakes when needed.

Building pressure too slowly might suggest issues with the compressor or air system, potentially leading to delays in braking performance, which can compromise safety.

In practical scenarios, fire apparatus are expected to have their air systems function efficiently, allowing for quick readiness in emergencies. Therefore, the 45-second mark is established as a benchmark that reflects operational readiness and safety compliance within the fire service guidelines.