GM OEM L5P Brake Master Cylinder. Genuine GM part is guaranteed by GM's factory warranty.
GM Genuine Parts Brake Master Cylinders are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These brake master cylinders are part of the hydraulic braking system that stores the brake fluid. When the brake pedal is applied, pressure is forced against a small moveable piston in the master cylinder. This pushes the hydraulic fluid through the lines and forces the brake pads against the disc brake rotor.