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 engine compartment, mounted on the power brake booster. If necessary for clearance, remove components such as the suspension upper brace on 1989 and earlier models, or the air cleaner assembly and engine wire bracket on 1990 and later models. Remove as much fluid as possible from the reservoir with a syringe, place rags under the fittings, and prepare caps or plastic bags to cover the ends of the lines once they're disconnected, taking care to avoid spilling brake fluid. Loosen the fittings at the ends of the brake lines where they enter the Brake Master Cylinder, unplug the electrical connector, and remove the mounting nuts. Pull the brake lines away from the Brake Master Cylinder and plug the ends to prevent contamination. Disconnect the electrical connector at the Brake Master Cylinder, then remove the nuts attaching the Brake Master Cylinder to the power booster and pull it off the studs. Before attempting the overhaul, obtain the proper rebuild kit. Remove the reservoir retaining screw, pull off the reservoir, and remove the grommets. Place the cylinder in a vise and use a punch or screwdriver to depress the pistons until they bottom against the other end of the Brake Master Cylinder, then remove the stopper bolt. Carefully remove the snap-ring at the end of the Brake Master Cylinder and then remove the internal components from the bore, making a note of the proper order of the components. Inspect the bore of the Brake Master Cylinder for damage, as any deep score marks will require a new Brake Master Cylinder. Replace all parts included in the rebuild kit, cleaning reused parts with new brake fluid or brake system cleaner, and lubricate all parts liberally with clean brake fluid during reassembly. Push the assembled components into the bore, bottoming them against the end of the Brake Master Cylinder, then install the stopper bolt and new snap-ring. Install the reservoir grommets, reservoir, and screw. Before installing the Brake Master Cylinder, it should be bench bled by mounting it in a vise and inserting threaded plugs into the brake line outlet holes. Fill the reservoir with brake fluid and expel air from the Brake Master Cylinder by pushing the piston assembly into the bore. Repeat the procedure until only brake fluid is expelled, ensuring the reservoir remains filled. For installation, place 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, then tighten the mounting nuts and brake line fittings. Fill the Brake Master Cylinder reservoir with fluid, then bleed the Brake Master Cylinder and the brake system, checking the operation of the brake system carefully before driving the vehicle.
Posted by ToyotaPartsDeal Specialist 
