How to Put in a Brake Master Cylinder
If your brakes are feeling spongy or the pedal is going all the way to the floor, it could signal a leaking or faulty brake master cylinder, and the safety of you and your passengers could be at risk. Luckily, a faulty brake master cylinder can be corrected quickly, and relatively easily.
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Things You'll Need
- Protective eyewear Open-end and box wrenches Line wrench Screwdrivers New master cylinder Bleeder kit Brake fluid Plastic dropcloth
Instructions
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Follow instructions included in your brake bleeder kit prior to installing the master cylinder. Bleeding is the process of removing all air from the brake fluid in the master cylinder, and should never be skipped, as air in the brake lines can and does cause catastrophic brake failure. Keep the brake fluid reservoir filled with fluid during the entire bleed process. Secure the master cylinder and pump the brake with the provided plastic rod. Pinch the rubber tubes prior to allowing the cylinder to return. Open the lines again, pump the cylinder, pinch the lines and release. Continue the process until there are no longer air bubbles rising from the tubes or reservoir.
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Place the brake master cylinder in its mounting and secure nuts tightly using a box or open-end wrench. Do not tilt and lose fluid from the reservoir, or you must repeat the bleeding process.
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3
Connect the brake lines to the master cylinder using a line wrench. This wrench is specially designed to install hydraulic fittings without rounding the ends. Wipe with clean dry cloth and check for any obvious leaks.
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Connect the wiring harness that provides power for the brake fluid level and pressure warning switch. It should be a snug fit.
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Top off brake fluid and begin the process of bleeding the brake system using the brake bleeder valves. There is a valve located on the inside of each wheel hub. This process is more efficient if done by two people. The first person will attach a clear rubber tube to the end of each opened bleeder valve. The second person will pump the brakes repetitively. The first person will watch the rubber tube and signal to stop pumping brakes when no more bubbles are visibly entering the tube. The first person will rotate the tube over all four valves until the air is out of the braking system. The brakes should be loose at first and gradually firm up as the air is removed.
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Tips & Warnings
Bleed the master cylinder in a location close to the vehicle it will be installed in. This reduces the chances of dropping or tripping. Invest in a line wrench to keep from rounding the ends and having to replace the brake line itself, which can be costly and time-consuming.
Wear protective eyewear to keep brake fluid from entering the eyes. Brake fluid is caustic and can ruin a paint job. Use a dropcloth over the side of the vehicle to protect the finish. Wash away any that does get spilled with water right away.
References
- Photo Credit All images courtesy of Photobucket photo pool
