OEM 2005 Cadillac STS Brake Master Cylinder

2005 Cadillac STS Brake Master Cylinder Parts Questions & Experts Answers

• Q: How to overhaul the brake master cylinder on 2005 Cadillac STS?

  A: Start Brake Master Cylinder overhauls by taking out the unit from your vehicle and placing the mounting flange in a bench vise to access the rear of the primary Piston. First clean the cylinder reservoir exterior and remove its cap then diaphragm for examination. Check for damage on both parts including cuts, cracks, chips and misshapen areas. Replace any defective components. Tools allows the removal of the primary Piston assembly when you push the Piston down using a smooth tool. Using filtered low-pressure air pipe the rear outlet port of the cylinder while plugging its inlet ports. Use the clean denatured alcohol on the master cylinder outside and inside surfaces plus secondary Piston and return spring. Then check for damage signs like corrosion before reinstalling with a new part if needed. Use filtered air to dry these parts and apply delco supreme 11 brake fluid (GM P/N 12377967, Canadian P/N 992667) or its equivalent dot-3 approved brake fluid as lubricant for the master cylinder bore and all components. Insert the new primary seal elements including their retainers into the secondary Piston while adding the secondary seal. Next add the lubricated return spring and secondary Piston assembly into the cylinder bore followed by the new primary Piston assembly. Use a smooth rounded tool to push down the new Piston retainer in place before reinstalling the master cylinder reservoir parts and putting the unit back into the vehicle.