Toyota 47201-34020 Brake Master Cylinder Sub-Assembly

Before fixing the Brake Master Cylinder, check if you can find and afford a new Brake Master Cylinder or a factory rebuild, plus whether a rebuild kit is available. Wipe up the brake line points first, then get ready to cap off the lines when disconnected. Brake fluid hurts paint, so use cloth to trap it; mask all colorful areas and work carefully to prevent spills. Pull out the electrical plug for the brake fluid level warning switch. Take off the tube nuts at the Brake Master Cylinder end of the brake lines with a flare-nut wrench, then use plugs to seal the brake lines to keep dirt out. Take off the four Brake Master Cylinder mounting bolts while protecting the hydraulic lines from kinking. Pull the Brake Master Cylinder out of your vehicle. Take off the reservoir cap and throw away the fluid left inside. If you take out the Brake Master Cylinder, you need to empty and refill the whole hydraulic system. It takes less time to bleed the system if you start with fluid in and bench bleed the Brake Master Cylinder before putting it back in. Place the Brake Master Cylinder in a vise using gentle, soft-clamping jaws on its flat side. Then fill its two fluid containers with brake fluid. Shield the openings where brake lines connect with your fingers to keep air from sucking back into the Brake Master Cylinder, then push on the piston several times slowly to get all air out while pressing down with a large Phillips screwdriver. Give several seconds each time before pushing down the piston again, while making sure your fingers block the holes before letting go. Put plugs in the holes for now and install the Brake Master Cylinder in reverse order. After that, bleed the brake system.