What type of brake wear is most indicative of a failing caliper piston?

Tapered brake wear, where one side of the brake pad is significantly more worn than the other, is the most indicative sign of a failing caliper piston. A caliper piston is responsible for pushing the brake pad against the rotor when the brakes are applied. If the piston is sticking, seized, or not retracting properly, it can cause the brake pad on that side to remain in constant or near-constant contact with the rotor. This continuous friction leads to accelerated wear on the affected brake pad, resulting in a noticeable taper. The uneven wear pattern indicates that the piston is not moving freely within the caliper bore, and is not releasing pressure evenly across the brake pad surface. This condition can also lead to overheating of the brake components, reduced braking efficiency, and potential damage to the rotor. Other causes of brake wear exist, but tapered wear strongly suggests a problem with the caliper piston itself.