What is the maximum allowable decrease in reservoir pressure after one full brake application for a vehicle to pass inspection?

The correct maximum allowable decrease in reservoir pressure after one full brake application is 18 p.s.i. This standard is important when assessing the function of a vehicle's air brake system, ensuring that it maintains sufficient pressure to operate effectively and safely. If the pressure drops beyond this threshold, it indicates that the air brake system may not be functioning properly, which can lead to reduced braking effectiveness and potentially compromise safety on the road.

This standard is set to ensure that vehicles can rely on their braking systems under various operating conditions, thereby enhancing overall road safety. Maintaining the proper reservoir pressure after a brake application is crucial because it ensures that the brakes will engage fully and respond reliably when needed. Therefore, for a vehicle to pass inspection, it must have less than an 18 p.s.i. decrease in reservoir pressure following one full application of the brakes.