What action should be taken if the air pressure drops below 90 psi?

When the air pressure drops below 90 psi, it signals a potentially unsafe condition in the braking system. At this point, the driver should prioritize safety and take immediate action by parking the vehicle and checking for leaks.

A drop below 90 psi indicates that the air brake system may not function effectively, posing a serious risk while driving. The operational integrity of air brakes is crucial for safe stopping and controlling the vehicle. If the system is not producing adequate pressure, it may lead to brake failure, increasing the danger of an accident. By parking the vehicle and inspecting the air system, the driver can identify issues such as leaks or malfunctions that need to be addressed before resuming driving.

Continuing to drive in this condition, activating the parking brake, or ignoring the drop in pressure would not address the risk associated with insufficient braking power, potentially leading to hazardous situations on the road.