PowerStop SW-0478 Disc Brake Pad Wear Sensor Fits select: 2011-2017 BMW X3, 2015-2018 BMW X4

We have a wide program of Brake Wear Sensors. You can rest assured that the Power Stop reputation for precision and adherence to the strictest OEM standards extends to our Aftermarket program for Brake Wear Sensors. Designed to meet the same form, fit, and function as the original OEM part. We pride ourselves to meet or exceed OEM requirements. Brake Wear Sensors are designed to fail. When they do, it's time to replace the brake pads, as well as the sensors. The most common type of electronic wear sensors are mounted into the brake pad itself. Our sensors are designed to withstand high temperatures and assure good electrode conductivity. On some applications the wear sensor is embedded into the pad and not removable; therefore they are only available with the brake pad. When the brake pad wears down to its discard thickness due to contacting the rotor while braking over the course of time, the sensor will make contact to the rotor, thus grounding the sensor. This will cause a brake warning light to illuminate on your dash or instrument cluster. It indicates that the brake pad friction material is almost gone and that replacement brake pads are needed. The mechanical brake pad wear sensors are small metal tabs on the backing plate of a brake pad. They are designed to contact the brake rotor surface and make a squealing or scraping noise when the brake pads have worn down to the point of needing replacement. The Power Stop Brake Wear Sensors continue to work after thousands of miles, providing the safety and performance drivers count on.