Removal and replacement of your master brake cylinder is a fairly straightforward procedure. Follow these 9 simple steps carefully and your project should run smoothly:
1. Be careful of spilled brake fluid. It can damage paint, so cover all body parts and painted surfaces. Place rags under the brake line fittings and cover the ends of the lines with caps or plastic bags when you disconnect them. Also, remember to dispose of any used fluids in a proper, environmentally responsible way. As always, be sure to wear proper eye protection and follow sensible, standard safety procedures. If fluid comes in contact with your eyes, immediately flush them out with water and seek medical attention.
2. Carefully loosen the tube nuts at the ends of the brake line fittings where they attach to the master brake cylinder. Take extra care not to round off the flats of the nuts as you loosen them. Use a flare-nut wrench because it wraps around the nut.
3. Pull the brake lines slightly away from the master cylinder and plug the ends to prevent debris or other contamination.
4. Remove the master cylinder by removing its mounting nuts.
5. Remove the cover and diaphragm assembly together from the reservoir and discard any remaining brake fluid.
6. The decision to either replace or overhaul the master cylinder is based on cost, availability, and your experience. There are also factory rebuilt kits (with warranties) available for purchase, as well as new ones.
7. Carefully install the new or rebuilt master cylinder by following the removal steps in reverse order.
8. Refill the master cylinder and replace the cover and diaphragm assembly.
9. Bleed the brakes to remove any air that has managed to find its way into the hydraulic system.
Remember: Safety first. Always be sure to wear proper eye protection and follow standard safety procedures.