What is the normal primary and secondary air gauge reading for a vehicle?

The correct answer reflects the normal operating pressure range for the primary and secondary air gauges in a commercial vehicle, which typically indicates a pressure of 110 to 120 psi. This range is important as it ensures that the air brakes function properly. Insufficient air pressure can lead to brake failure, while excessively high pressure might indicate a malfunction in the air system.

Understanding these pressure readings is critical for ensuring that the air brake system is functioning safely and effectively. Regular pre-trip inspections should include checks of the air pressure gauges to verify they are within the appropriate range, thereby contributing to overall vehicle safety and performance on the road. This knowledge is essential for drivers to maintain their vehicles and ensure compliance with safety regulations.