What do brake lines do? Why buy brake lines?
Brake lines connect the master cylinder to the calipers. The brake lines contain brake fluid so the fluid can push against the caliper every time the brakes are pressed on, thereby stopping you. Old rubber brake lines expand under pressure, so that instead of the brake fluid pushing the caliper, the fluid stretches the brake line and reduces the maximum performance of the brakes by making your pedal feel spongy. New brake lines combat this problem giving you maximum braking performance and a nice tight pedal feel.
