What does brake dust typically indicate?

Brake dust is primarily a byproduct of the friction and wear that occurs during the braking process. When brake pads engage the rotor, especially under heavy use, microscopic particles are generated as the pad material wears away. The presence of brake dust can indicate that the brake components are working as intended, but it often points to the fact that the brake pads are beginning to wear down. If brake dust accumulation is excessive, it may signal that the pads have reached a level of wear that necessitates replacement to maintain effective braking performance.

In contrast, the other options do not directly correlate with the presence of brake dust. A vehicle running efficiently may produce less brake dust owing to lighter use, but this is not a definitive indicator of brake performance. Clean brake fluid suggests that the brake system is free of contaminants, which is unrelated to the wear of brake pads, while properly inflated tires do not influence brake dust production. Thus, the accumulation of brake dust is a clear indicator that the brake pads may be worn and require attention.