When the brake fluid shows signs of high levels of copper content, the additives in the brake fluid are breaking down. This increases acid levels and causes erosion of parts and possible damage to Anti-Lock Brake System components. Today’s anti-lock brake systems are expensive – some parts cost thousands of dollars, not including labor. Changing your brake fluid protects this investment.
Some manufacturers recommend new brake fluid as often as every two years. You also need to change your brake fluid if it contains too much copper. Copper is measured in parts per million, and the industry-accepted limit is 200 ppm. Any more than that and the fluid no longer meets design specifications and should be replaced.