The Toyota disc brake rotors have two flat surfaces on opposite sides of the disc where the pads make contact and create the friction that stops your vehicle. The pads are held in place on both sides of the brake rotors by the brake caliper which is the component that creates the squeezing action for the friction to be created. If the Toyota is maintained properly including regular brake jobs before the brake pads are worn totally out, then the brake rotors can last for as long as the vehicle is being driven on the road. The most common incident where damage will occur to the disc-like surface of the Toyota brake rotors is when the owner of the vehicle neglects to have their vehicle in the repair shop for a periodical brake job replacing the brake pads before they wear out. The damage to the disc brake rotors is inflicted by the backing plate of the brake pads that make contact with them when all of the padding material they once had has been depleted. This backing plate is made out of material that is just as hard as the brake rotors. When they are forced together and friction is created, grooves are cut into both of them, damaging them along with decreasing the ability of your brake system to slow your Toyota down. Once this damage is inflicted on the rotors, the Toyota owner will have to have them turned on a lathe if the grooves are not too deep. This will restore the flat surfaces once again so the new brake pads can create friction without prematurely wearing out.