Remove top engine cover. Remove strut brace from between the strut towers. On 2004 and later Lexus models, remove cowl tray from engine compartment. Remove air filter housing. Remove as much fluid as possible from reservoir with syringe. Unplug electrical connector for brake fluid level warning switch. Place rags under fittings and prepare caps or plastic bags to cover ends of lines once disconnected. Loosen fittings at ends of brake lines where they enter Brake Master Cylinder. Carefully move brake lines away from Brake Master Cylinder and plug ends. Remove nuts attaching Brake Master Cylinder to power booster. Pull Brake Master Cylinder off studs to remove it. If necessary, remove brake lines going to ABS actuator from Brake Master Cylinder. Caution: If Brake Master Cylinder is dropped, it must be replaced. Installation: Bench bleed new Brake Master Cylinder before installing it. Attach pair of Brake Master Cylinder bleeder tubes to outlet ports of Brake Master Cylinder. Fill reservoir with recommended brake fluid. Slowly push pistons into Brake Master Cylinder to expel air. Repeat procedure until no more air bubbles are present. Remove bleed tubes and install plugs in open ports. Adjust booster pushrod length if installing new Brake Master Cylinder. Install reservoir cover, then install Brake Master Cylinder over studs on power brake booster and tighten attaching nuts finger tight. Thread brake line fittings into Brake Master Cylinder. Tighten mounting nuts and brake line fittings securely. Fill Brake Master Cylinder reservoir with fluid, then bleed Brake Master Cylinder and brake system. If necessary, bleed lines at ABS actuator. The remainder of installation is the reverse of removal. Test operation of brake system carefully before placing vehicle into normal service.