GM 84543716 Cylinder Assembly, Brk Mas

Take off the negative cable from the battery, detach the electrical wire connected to the warning switch, and get as much old brake fluid as you can from the container by using a vacuum to suck it out via a special brake fluid device. Put rags under the hose fittings before you disconnect the lines. Get ready with containers-a cap or plastic bag to cover each line after it's disconnected. To protect the nuts on the brake line fittings, loosen them with a flare-nut wrench instead of using a normal nut wrench. Cover the open ends of the brake lines with water-proof plugs before moving them away from the brake master cylinder. Take out the bolts holding the brake master cylinder to the power booster, then gently pull the cylinder away from the bolts to keep fluid from spilling. Start bleeding air out of the brake master cylinder before putting it in by holding it steady in a vise and placing valves on the outlet ports. To empty air out of the brake master cylinder, use the right fluid and push its pistons one by one into the unit until only clear fluid comes up in the tank. Repeat until you no longer see bubbles. Place stopper plugs into each port as you remove bleed tubes one at a time, and put the reservoir cap back on. Put a new O-ring on the brake master cylinder end, attach it to the booster without tightening the mounting nuts with your fingers, and screw the brake lines into the brake master cylinder being careful not to screw the threads off. Put mounting nuts onto the correct fit and completely close all brake line connections. Add brake fluid to the master reservoir first, let fluid run out through master bleeder valves, then use normal bleeding methods to explore the whole brake system until all spots stop leaking. To replace O-rings and the reservoir, drain as much fluid as you can from the canister, apply paper towels underneath to absorb leaks, gently slide out the reservoir from the brake master cylinder, install brand new O-rings carefully, coat them with brake fluid, set the reservoir into place securely, fill up with proper brake fluid, and look for fluid leaks.