A: When dealing with a defective Brake Master Cylinder, it is recommended to replace it with a new one as rebuilding is not advised by the manufacturer. For removal, locate the Brake Master Cylinder in the engine compartment, mounted to the power Brake Booster. Remove as much fluid as possible from the reservoir using a syringe. Place rags under the fluid fittings and prepare caps or plastic bags to cover line ends after disconnection. Loosen the tube nuts at the brake line ends where they enter the Brake Master Cylinder, using a flare-nut wrench to prevent corner rounding. Disconnect the electrical connector and remove the nuts attaching the Brake Master Cylinder to the power booster. Carefully pull off the Brake Master Cylinder, ensuring no fluid spillage. During installation, bench bleed the new Brake Master Cylinder by attaching Brake Master Cylinder bleeder tubes to the outlet ports and filling the reservoir with recommended brake fluid. Slowly push the pistons into the Brake Master Cylinder to expel air into the reservoir, repeating until no air bubbles are present. Remove the bleed tubes, install plugs, and reservoir cover. Install the Brake Master Cylinder over the power brake booster studs, thread brake line fittings into the Brake Master Cylinder, and tighten mounting nuts and brake line fittings securely. Fill the reservoir with fluid, bleed the Brake Master Cylinder and brake system as described, and test brake system operation before normal use.