Before deciding to overhaul the Brake Master Cylinder, check on the availability and cost of a new or factory rebuilt unit and also the availability of a rebuild kit. The Brake Master Cylinder is located in the front luggage compartment behind the trim cover, which can be removed by disengaging the two clips with a small screwdriver. Remove as much fluid as possible from the reservoir using a syringe, and place rags under the fluid fittings while preparing caps or plastic bags to cover the ends of the lines once disconnected, taking care to avoid spilling brake fluid, which can damage paint. Loosen the tube nuts at the ends of the brake lines with a flare nut wrench to prevent rounding off the flats, then pull the brake lines slightly away from the Brake Master Cylinder and plug the ends to prevent contamination. Disconnect the electrical connector at the Brake Master Cylinder, remove the four nuts attaching it to the power booster, and carefully pull the Brake Master Cylinder out of the luggage compartment. Before overhauling, obtain the proper rebuild kit containing necessary replacement parts and any specific instructions. Inspect the reservoir grommet for leakage, remove the reservoir by releasing the set bolt and hose clamp, and separate it from the Brake Master Cylinder. Place the cylinder in a vise and fully depress the pistons using a wooden dowel, then remove the stop bolt, outlet plugs, and copper gaskets. Carefully remove the snap ring at the end of the Brake Master Cylinder and take out the internal components, noting their order, as the two springs have different tensions. Inspect the inside bore for deep scoring or damage, which would require a new Brake Master Cylinder. Replace all parts included in the rebuild kit, clean reused parts with brake fluid or denatured alcohol, and lubricate all parts with clean brake fluid during assembly, ensuring all fittings are tightened to the specified torque. Push the assembled components into the bore, install the stop bolt, and the new snap ring. Before installing the new Brake Master Cylinder, it should be bench bled by mounting it in a vice, inserting threaded plugs into the brake line outlet holes, and filling the reservoir with the recommended brake fluid. Remove one plug and push the piston assembly to expel air, replacing the plug before releasing pressure. Repeat until only brake fluid is expelled, then use an alternative method by covering the hole with a finger instead of replacing the plug. Install the Brake Master Cylinder over the studs on the power brake booster and tighten the attaching nuts finger tight. Thread the brake line fittings into the Brake Master Cylinder, ensuring they are not stripped, then fully tighten the fittings and mounting nuts. Fill the reservoir with fluid, bleed the Brake Master Cylinder if it hasn't been bench bled, and bleed the brake system by having an assistant pump the brake pedal and hold it to the floor while loosening the fitting nut to allow air and fluid to escape, repeating until the fluid is clear of air bubbles. Test the operation of the brake system carefully before placing the vehicle in normal service.
Posted by ToyotaPartsDeal Specialist 
