Abstract: A wear indicator for a disk brake having a caliper that slides in a carrier to apply friction pads against a disk. The wear indicator comprises a continuous variation sensor, such as a capacitive sensor, connected to a monitor. The capactive sensor has first and second electrodes having a variable overlap area. A guide pin for the caliper forms the first electrode. As the guide pin moves during a brake application, the monitor periodically measures the overlap area to define a current operational output signal which is compared with a predetermined signal and when the comparison differs from a normal result a failure signal is provided to indicate that the disk brake in not properly operating.