What indicates that brake linings need to be replaced?

The indicator that brake linings need to be replaced is the metallic scraping sound against the rotor. This sound typically occurs when the brake linings have worn down to the point where the brake pad material is no longer sufficient for effective braking. When the pads wear out, a metal backing plate may come into contact with the rotor, producing a distinct and often alarming scraping noise. This warning sign not only indicates that immediate attention is necessary to prevent further damage to the braking system but also ensures the safety of the vehicle as compromised brakes can significantly affect stopping power.

In addition, increased travel of the brake pedal and malfunctioning brake lights may reflect other issues within the braking system but do not directly indicate that the brake linings need replacement. A loud honking sound is typically unrelated to brake performance and instead could be linked to other mechanical or electronic issues within the vehicle. Therefore, the metallic scraping sound is the most relevant and critical sign that brake linings are due for replacement.