OEM 2004 Cadillac Seville Brake Master Cylinder

2004 Cadillac Seville Parts Questions & Experts Answers

• Q: How to overhaul the brake master cylinder on 2004 Cadillac Seville?

  A: Bolt the Brake Master Cylinder mounting flange into a bench vise to work on it. This should provide access to the primary Piston. First sanitize the area around the cap on the master cylinder reservoir before you take off its components to examine them for damage and order new parts when needed. To start the repair use a smooth tool to push down the primary Piston through the master cylinder reservoir and take out the Piston retainer before pulling out the primary Piston assembly from its bore. Set all master cylinder ports in place and use controlled air to push out the secondary and primary components with their seals as well as the return spring. Keep the primary Piston assembly, Piston retainer, and seals for discarding. Clean all surfaces of the master cylinder assembly plus secondary Piston and return spring with denatured alcohol while looking for damage which requires replacing the master cylinder if found. Use filtered breathers to clean all parts and apply brake fluid from delco supreme ii, gm pin 12377967 (Canadian P/N 992667), or equivalent dot-3 brake fluid directly onto the master cylinder bore, return spring, secondary Piston, and professional overhaul components. Place the two lubricated seals onto the secondary Piston next put on the return spring and secondary Piston assembly. After that install the lubricated primary Piston assembly. Insert the new Piston retainer using a rounded tool tool and place it into the master cylinder Piston. Reconnect the reservoir parts and put back the master cylinder for vehicle installation.