OEM Buick LaCrosse Brake Master Cylinder

Buick LaCrosse Brake Master Cylinder Parts and Q&A

• Master Cylinder
  19209278
  Q: How to overhaul the brake master cylinder on Buick LaCrosse?

  A:

  Before you start you must remove the master cylinder from the vehicle and clamp its mounting flange in a vise with space to access the back of the primary Piston. At first clean the area around the cap of the master cylinder reservoir then check the parts inside for damage before replacing them. The master cylinder reservoir must be detached and a round-ended tool used to push down the primary Piston before removing the Piston retainer, and the primary Piston assembly. Duet the holes of ports and connect front outlet tube to an airflow generator applying filtered non-lubed air to extract the secondary seal unit. Take out the main Piston piece along with the Piston retainer and both seals that belong to the secondary Piston. Use denatured alcohol to wash the master cylinder's inside and outside while replacing it when damage shows up during examination. Use filtered non-oiled air to dry components and add delco supreme 11 liquid brake fluid (GM P/N 12377967 or equivalent) to the master cylinder bore, secondary Piston , return spring, and all service parts from a fresh sealed container. Place the new primary seal and retainer onto the secondary Piston with its secondary seal installed. Put in the return spring and secondary Piston assembly lubricated with new primary Piston set after placing them into the cylinder bore. Depress the primary Piston with a smooth tool before adding its new retainer piece. Attach the master cylinder reservoir components and finally place the master cylinder in its vehicle position.
• Master Cylinder
  18022002
  Q: How to Properly Handle the Brake Master Cylinder Replacement Process on Buick LaCrosse?

  A:

  The first step involves disconnecting power from the brake fluid sensor and brake lines before removing the Brake Master Cylinder. Insert rubber caps over brake pipe ends to seal the open ports. Put plugs on exposed brake ends before loosening the master cylinder nuts and removing the unit from the vehicle while letting all brake fluid drain from the reservoir. Before connecting the master cylinder to the vacuum Brake Booster, always bench bleed the system and then install both mounting nuts tight to 33 n.m (24 lb ft). Fasten brake pipe connections to the master cylinder using 30 n.m (22 lb ft) torque when the vehicle has abs system but only 27 n.m (20 lb ft) for the front brake fittings and 25 n.m (18 lb ft) for the rear fittings without abs. Join the electrical connector back to the brake fluid sensor while letting brake fluid flow through the system.