OEM 2004 Chevrolet Classic Brake Master Cylinder

2004 Chevrolet Classic Brake Master Cylinder Parts and Q&A

• Q: How to overhaul the brake master cylinder on 2004 Chevrolet Classic?

  A: Start your Brake Master Cylinder overhaul by taking it off the vehicle then setting the mounting flange in a vise to work on the back of the main Piston. You must clean the exterior of the reservoir near the cap before you take off the cap and diaphragm to see if the parts have damages or require replacement. Use a smooth tool to push down the primary Piston as you remove its retainer and then retrieve the primary Piston assembly from the cylinder bore. On the cylinder inlet ports and rear outlet plug the setup and feed low pressure non-lubricated filtered air to remove the secondary Piston unit, including both primary and secondary seals as well as the return spring. Discard the primary Piston hardware for safe disposal. To rebuild the master cylinder you must clean all internal and external parts including the secondary Piston and return spring with denatured alcohol. Check for damage such as cracks, scoring, and corrosion then replace the system if damage is found. Introduce each component to non-lubricated filtered air before adding delco supreme 11(R) brake fluid specified by gm p/n 12377967 or canadian equivalent p/n 992667 to all work parts and the master cylinder bore, secondary Piston, return spring, and secondary Piston assembly. Position the lubricated new primary seal and retainer unit alongside new secondary seal before adding the return spring and secondary Piston assembly into the cylinder bore. Insert the building blocks to place new primary Piston above them for assembly. Use a rounded tool to press down the primary Piston and put in the new Piston retainer. Next, reassemble the master cylinder reservoir and its parts while installing the entire unit to the car.