Brake pad glazing occurs when braking temperatures exceed the limits of the brake pad friction material, causing the pad material to harden and form a glassy, smooth pad surface. Glazing results in excessive stopping distances, poor braking performance, and can happen without the drivers knowledge. Glazing can be caused by repeated hard and rapid braking at higher speeds, driving with a foot on the brake pedal, or riding the brakes, which keeps the pads in contact with the rotor. Glazing can also occur due to hydraulic or mechanical failures of the caliper. Glazed brake pads should be replaced, and the rotors cleaned or replaced. Signs that brake pads are glazed include poor stopping performance, vibration or brake judder, cracks or fissures in the brake pad material, and a shiny or crystallized appearance on the surface of the pads. To check for glazing, visually inspect the brake pads and run your finger over the surface of the pads. If the surface is smooth, it indicates glazing.