Brake Pad Wear Sensor: Description and Operation

Brake pad, front wheel





The acoustic wear warning device consists of an L-shaped strip of sheet metal affixed to the outer brake pad on the front wheels.
The metal strip comes into contact with the brake disc when the thickness of the friction material is less than 3 mm (0.12 inch).
The metal strip then makes a scraping or intermittent screeching noise which warns the driver of worn brake pads.