To remove the brake master cylinder, first disconnect the cable from the negative terminal of the battery. Unplug the electrical connector for the fluid level warning switch, and for manual transmission vehicles, disconnect and plug the clutch fluid hose. Use a syringe to remove as much fluid as possible from the reservoir, then place rags under the fittings and prepare caps or plastic bags to cover the ends of the lines after disconnection, taking care to avoid spilling brake fluid, which can damage paint. Loosen the fittings at the ends of the
Brake Lines where they enter the brake master cylinder using a flare-nut wrench to prevent rounding off the flats. Pull the brake lines away from the brake master cylinder and plug the ends to prevent contamination. Remove the nuts attaching the brake master cylinder to the power booster and pull the brake master cylinder off the studs, being cautious not to spill any remaining fluid. For installation, bench bleed the new brake master cylinder by mounting it in a vise and attaching a pair of bleeder tubes to the outlet ports. Fill the reservoir with the recommended brake fluid and slowly push the pistons into the brake master cylinder to expel air into the reservoir, repeating until no more air bubbles are present. Remove the bleed tubes one at a time, install plugs in the open ports, and then install the reservoir cap. Place a new O-ring seal in the groove on the end of the brake master cylinder, coat it with silicone grease, and also coat the bore of the power
Brake Booster. Install the brake master cylinder over the studs on the power brake booster and tighten the nuts finger-tight. Thread the brake line fittings into the brake master cylinder, ensuring they thread in easily without stripping the threads. Tighten the mounting nuts to the specified torque and secure the brake line fittings. Fill the brake master cylinder reservoir with fluid, then bleed the lines at the brake master cylinder, followed by the remainder of the brake system, having an assistant depress the brake pedal while loosening the fitting to allow air and fluid to escape, repeating until the fluid is clear of air bubbles. After tightening the fitting, allow the assistant to return the pedal to its rest position and check the operation of the brake system carefully before driving the vehicle. Finally, reconnect the battery and perform the necessary re-learn procedures.