Master Cylinder
If you want to do it yourself, you will need to learn how to replace abrake master cylinder. The most common reason to replace a brake master cylinder is due to internal leaks and worn out parts. Master cylinder components wear out after miles of service. Fortunately, this is not a complicated job repair project, but you do need to pay attention to detail and careful handling of the master cylinder and system components to prevent damage and contamination. This project requires a few common tools and a couple of hours or more of work at home.Removing the brake master cylinderThe master cylinder is mounted on thebrake booster. This is the round, drum-like component on the driver's side of the firewall in the engine compartment. First, you will need to disconnect the electrical connector and the brake lines from the master cylinder. For the lines, use only a line wrench to prevent damage to the line nuts. After disconnecting the lines, you will need to cap the openings to prevent dirt or grease from entering the system. You can use a piece of clean plastic and a rubber band for this. Finally, unscrew the faulty master cylinder from the brake booster.On some vehicle models, you need to disconnect the push rod that activates the master cylinder through the brake booster. The push rod connects to the brake pedal on the other end. If you need to disconnect it, remove the mounting clip securing the rod to the pedal and the mounting washers. Make a note of the position of each part and how they all fit together, so that you can reinstall everything in its original place.Bleeding the new brake master cylinderYou can buy a brand new or re-manufactured unit. Either way, compare the old master cylinder to the new one to make sure you have the correct replacement. Then, you can go ahead and bleed it. You can do this by mounting the cylinder on a vise and connecting a couple of plastic lines of the correct diameter to the brake line fittings of the new cylinder. Bend the other end of the lines into the reservoir compartments. Fill the reservoir with new brake fluid and pump the cylinder using a Phillips-head screwdriver as if it were the push rod. Cover the screwdriver tip with a rag to prevent damage to the master cylinder. Once all the air bubbles have been removed from the plastic lines, the cylinder is ready for installation.Installing the brake master cylinderConnect the push rod to the brake pedal, if necessary. Secure the cylinder to the brake booster, but do not tighten the nuts yet. Connect the brake lines by hand first to prevent cross threading the mounting nuts. Tighten the brake lines with the line wrench and then the cylinder mounting nuts. You have just replaced the brake master cylinder on your car. Now, take your vehicle to a service shop and have thembleedthe brake lines to remove any air that might’ve found its way into the system during the installation process.
