Hydraulic System

Two major concerns can occur in hydraulic brake systems: external leaks, and master cylinder bypass (internal leak). Hydraulic brake systems and their components, the master cylinder and valves, do not cause the vehicle to vibrate or pull, the brakes to grab or squeal, or the brake pedal to pulse. In most cases, they will not even make the brakes drag. The sources of these concerns are found elsewhere in the brake system, but it is always a good policy to first check the entire hydraulic system for leaks before continuing to diagnose any other brake concerns.