When inspecting the air pressure gauge, what must the inspector confirm?

When inspecting the air pressure gauge, the inspector must confirm that the gauge is within the normal range. This is crucial because the air pressure in the braking system impacts the vehicle's ability to stop effectively. A gauge indicating incorrect pressure could mean that the brakes may not function properly, leading to potential safety hazards on the road. Ensuring the gauge readings are within normal limits allows for the necessary adjustments or repairs to be made, thereby maintaining safe operation of the vehicle.

Other options do not align with safety and operational standards. For instance, a gauge that doesn't function poses a risk as it would prevent the driver from accurately assessing the air pressure. A damaged gauge could lead to incorrect readings, jeopardizing vehicle safety. Replacing the gauge might be necessary if it’s found to be defective, but it is not an initial requirement unless the gauge is found to be malfunctioning. The primary focus is on confirming that the gauge reflects the correct air pressure level to ensure the braking system operates effectively.