Brake fluid by nature is “hygroscopic” which means it has a tendency to absorb moisture. Many components in the brake system are metal and moisture is a natural enemy of metal. With the new ABS and traction control systems on vehicles when they activate they generate heat which breaks down the fluid. As brake fluid ages it can become contaminated with small particles which deteriorate the fluid and lowers the boiling point of the fluid which can affect the ABS and traction control systems. Fresh fluid also helps to keep failure rates low on expensive components like the ABS actuator which can cost several thousand dollars to replace.