OEM Buick Park Avenue Brake Master Cylinder

Buick Park Avenue Brake Master Cylinder Parts and Q&A

• Master Cylinder
  19209230
  Q: How to overhaul the brake master cylinder on Buick Park Avenue?

  A:

  To replace the Brake Master Cylinder, remove it from the vehicle and clamp the mounting flange in a bench vise with the rear of the primary Piston accessible. For the area around the reservoir cap, clean it before disconnecting it including the diaphragm and inspect them for cuts, cracks, nicks or deformation, and change the parts accordingly. The master cylinder reservoir should be removed, and then a smooth, round-ended tool should be utilized to push in the primary Piston, after which the Piston retainer, primary Piston assembly, and the cylinder bore will be removed. Plug the cylinder inlet ports and the outlet port at the rear of the cylinder, and introduce low pressure, non-oiled, filtered air into the front outlet port to strip the secondary Piston out with the primary and the secondary seals and the return spring, discarding the assembly of the primary Piston, piston retainer, and the seals. Clean the master cylinder, secondary Piston, and return spring on the inside and out using denatured alcohol and inspect it for cracks, scoring, pitting or corrosion and replace the master cylinder if there is any problem. Swab all components with non-lubricated, filtered air, and lubricate the master cylinder bore, secondary Piston , return spring, and all overhaul components with delco supreme 11 (R)(GM P/N 12377967) or equivalent dot-3 brake fluid from a clean sealed container. Mount the lubricated new primary seal and retainer onto the secondary Piston and the lubricated new secondary seal into second Piston assembly in the cylinder bore before inserting the lubricated new primary Piston assembly . Down with a smooth, round-ended tool depress the primary Piston and install new Piston retainer and return the master cylinder reservoir and its cap and diaphragm before reinstalling the master cylinder back to the vehicle.
• Master Cylinder
  19209255
  Q: How to replace the brake master cylinder on Buick Park Avenue?

  A:

  Before installation disconnect the brake fluid sensor electrical connector and the brake tubes from the master cylinder to prevent fluid leakage and contamination. After plugging open brake pipe fitting ends you can remove 2 master cylinder nuts then pull out the master cylinder. Take the reservoir off the master cylinder only when you want to keep it for further use. Install the Brake Master Cylinder reservoir assembly to the master cylinder first when it was removed during repair. Perform bench bleeding on the master cylinder before placing it on the vacuum Brake Booster. Use normal procedure except for the fastener requirement explained in service precautions. Install the master cylinder using its 2 mounting nuts until they reach 25 nm (18 ft. Lbs.) torque and proceed to attach the brake pipes to the master cylinder while tightening the fittings to 32 nm (24 ft. Lbs.). Reattach the electrical connector to the brake fluid sensor before you end the brake fluid bleeding process.