What noise might indicate worn brake pads?

A metallic squealing or grinding noise is a clear sign that brake pads are worn and likely need to be replaced. This sound is produced when the pad's friction material has worn down to the point where the metal backing plate makes contact with the brake rotor. The metal contact creates a harsh, metallic sound that serves as an audible warning to drivers that their brake pads are no longer providing effective stopping power and could lead to further damage if not addressed promptly. The grinding noise specifically indicates that the brake pads are severely worn, potentially compromising vehicle safety.

Other sounds like a soft humming noise, a high-pitched whistling noise, or a low rumbling sound do not specifically correlate with worn brake pads and may indicate different issues, such as problems with wheel bearings or other components in the brake system. Therefore, the metallic squealing or grinding noise is the most direct indicator of brake pad wear, highlighting the critical role of attentive listening in vehicle maintenance.