With the friction of the brake pads against the Subaru disc brake rotors your vehicle can have its forward momentum slowed so handling a corner can be made more manageable. This is possible since both sides of the disc-like surface of the brake rotor are flat and the friction can be smoothly applied. The brake rotor not only provides the location for the friction from the braking system to be created, but they also sometimes double as the wheel hubs. This provides for a place the wheels are mounted to with the wheel bearings in the center of it that support the weight of the Subaru. If the Subaru owner replaces their brake pads before they become worn, then the Subaru disc brake rotors can last for as long as the vehicle is being driven on the road. It is the backing plate the brake pads are mounted to that are the only components that can damage brake rotors and discs when they make contact with them. This is when the friction of the metal to metal contact cuts grooves into the previous flat and smooth surfaces. To help prevent this situation from happening, the owner of the Subaru must know the life expectancy of their brake pads and when it is appropriate to have them changed before they totally were out. The best indication that the brake pads are worn is to observe the fluid level in the brake master cylinder. As the brake pads wear, the fluid level in the appropriate reservoir drops. When it appears to be low, the brake pads should be inspected. This is the best way to save your brake rotors and discs from becoming damaged by contact with the metal backing plate of worn out pads.