Resins that bind pad compounds together are organic-petro-chemical products. When the Brake Pads reach high temperatures, the resins revert to gas and cause the pads to "aquaplane" on a film of gas (this is called "fade"). The friction force between the brake pad and disc is as a result reduced. Some pads only fade once or twice and then settle down (green fade or bedding-in fade) and then the performance stabilises. Many cheap low quality pads will suffer from continual dynamic fade, sometimes at surprisingly low temperatures.
Support - FAQs