OEM Buick Rainier Brake Master Cylinder

Buick Rainier Brake Master Cylinder Parts and Q&A

• Master Cylinder
  19209266
  Q: How to overhaul the brake master cylinder on Buick Rainier?

  A:

  Before performing Brake Master Cylinder overhaul workers should remove the component from the vehicle and put the mounting flange in a bench vise so they can access the rear of the primary Piston. Inspect the master cylinder reservoir cap and diaphragm for damage after cleaning their external surfaces before component replacement. Check for all visible defects such as cuts, cracks, nicks or deformation. The process starts by removing the master cylinder reservoir followed by using a smooth tool to push down on the primary Piston while removing the Piston retainer before extracting the primary Piston assembly from the cylinder bore. Use low pressure clean filtered non-lubricated air to blow the secondary Piston along with its primary and secondary seals and return spring while plugging the cylinder inlet ports and rear outlet port. Throw out the primary Piston assembly, Piston retainer, and seals. Thoroughly clean interior and exterior surfaces of the master cylinder and secondary Piston and return spring with denatured alcohol while keeping away from abrasive materials. Checks for damage like cracks, scoring, pitting, and corrosion require replacement of the master cylinder if present. All components need non-lubricated filtered air drying before you apply delco supreme 11 brake fluid p/n 12377967 (Canadian P/N 992667) or equivalent dot-3 grade fluid from a clean sealed fluid container to the master cylinder bore along with the secondary Piston and return spring and all overhaul parts. Accomplish assembly of the new primary seal combined with its retainer and secondary seal onto the secondary Piston before you put in the return spring and secondary Piston assembly in the cylinder bore and continue with the primary Piston assembly installation. Depress the primary Piston with a smooth tool through its primary Piston hole to install the new Piston retainer. Reinstall the master cylinder reservoir and its cap and diaphragm then secure the master cylinder assembly back into the vehicle.
• Master Cylinder
  15142479
  Q: How to replace the brake master cylinder on Buick Rainier?

  A:

  Start by engaging the parking brake then disconnect the sensors on top of the Brake Master Cylinder. After that remove the brake pipes at their connections with the master cylinder. It is necessary to put rubber plugs on the open ends of brake hoses to stop brake fluid from leaking and keeping the system clean. Unscrew the mounting hardware from the master cylinder and withdraw the unit while draining its fluid into a container. Only then perform bench bleeding on the master cylinder prior to its new installation. Hand-tighten the master cylinder mounting nuts but also apply 36 n.m (27 lb ft) torque to them. Attach brake pipes to the lines and tighten their fittings to 32 n.m (24 lb ft) while removing rubber plugs. End by connecting the master cylinder fluid level sensor while going through a brake system bleed process.