With the proper operations of the Kia brake rotors and discs in place, your vehicle can be brought to a controlled stop when it is necessary. This is the brake component that has the wheels connected to it. It is also the component where the force is applied to stop the rotation of the wheel. The surface on the brake rotors and discs where the pads are forced to apply pressure to must be as smooth as possible. This will minimize the wear on the brake pads over their life span on your Kia. The time when damage is inflicted on the Kia brake rotors and discs is when the brake pads wear down and are not replaced in a timely manner. Once all of the friction material the pads are made out of have been used up, the metal backing plate they are mounted to is exposed to the brake rotor and discs. It is this metal component that will then come into direct contact with the brake rotors and discs causing a loud grinding sound when the brake are applied. When a Kia owner hears this sound, it is already too late for a brake job to occur that only has the pads being replaced. The noise is grooves being cut into the flat surface on the rotors. These grooves will have to be removed or the new brake pads will prematurely wear. Most brake shops have a lathe which can remove the grooves from the brake rotors and discs. The only problem with this is that will make the discs thinner. There is a minimum thickness the rotors have to be on your Kia so the heat of the braking action can be dissipated. Once this thickness is no longer present, only replacement of the discs can restore the braking system of your vehicle to its proper working condition.