OEM 2003 Chevrolet Express 3500 Brake Master Cylinder

2003 Chevrolet Express 3500 Brake Master Cylinder Parts Questions & Experts Answers

• Q: How to overhaul the brake master cylinder on 2003 Chevrolet Express 3500?

  A: Set the vehicle Brake Master Cylinder on a bench vise with its mounting flange held securely and expose the rear of the primary Piston to perform maintenance. Use a clean cloth to clean the outside area around the reservoir cap then replace the cap and diaphragm unit before inspecting both for damage and replacing any faulty components. Disassemble the master cylinder reservoir while pushing the primary Piston down using a round tool. The Piston retainer and primary assembly should then come off the cylinder bore. Safe-check the port openings while blowing filtered air through the front port to take the secondary Piston inside out with its seals and spring. Take the primary Piston system and its parts out from the secondary Piston. First clean all parts of the master cylinder system including the secondary Piston and return spring using denatured alcohol. Check for damage such as cracks, deformation and corrosion before replacing the parts. After filtering all pieces with non-oiled air you should use delco supreme 11 brake fluid gm p/n 12377967 or equal dot-3 from sealed source to lubricate the master cylinder bore the secondary Piston the return spring and other parts. Place the lubricated primary seal and retainer alongside secondary seal onto the secondary Piston before inserting the lubricated return spring and secondary Piston assembly inside the cylinder bore. Finally add the lubricated primary Piston assembly. Put on a light master cylinder master cylinder tool and press down the primary Piston before you add the new Piston retainer. After that connect the master cylinder reservoir onto the vehicle.