OEM 2003 Buick LeSabre Brake Master Cylinder

2003 Buick LeSabre Brake Master Cylinder Parts and Q&A

• Q: How to service and repair the Brake Master Cylinder on 2003 Buick LeSabre?

  A: The procedure to fix the Brake Master Cylinder starts with mounting it in a bench vise to access the primary Piston. Mount suitable fittings that match the required flare seat at the master cylinder ports to allow you to attach hoses. Link transparent hoses to these fittings and bring them into the master cylinder reservoir space. Put delco supreme 11 brake fluid gm part number 12377967 or its equivalent dot-3 fluid into the reservoir from a sanitation-sealed container until the hoses and fluid bottom reach the halfway mark. Using a round smooth tool press and release the Piston into the primary chamber twice as depth reaches about 25 mm (1 in). Repeat until no more air bubbles appear from the ports and the tool loses its natural return path. Keep pushing the Piston movement until the ports release fluid without showing air pockets inside the system. Take off the transparent hoses from the reservoir then put back the master cylinder reservoir cap and diaphragm before separating the hoses from their connections at the ports while keeping the master cylinder wrapped with a clean cloth to avoid spills.