OEM 2005 Buick Rainier Brake Master Cylinder

2005 Buick Rainier Parts Questions & Experts Answers

• Q: How to perform bench bleeding of the brake master cylinder on 2005 Buick Rainier?

  A: You must secure the master cylinder mounting flange in a bench vise to properly conduct bench bleeding while having access to the rear side of the primary Piston. Set up suitable port fittings to match the required flare seat on the master cylinder ports and allow hose attachment before you remove the cap and diaphragm from the reservoir. Set up transparent hoses to the fittings and place them inside the master cylinder reservoir. Put delco supreme 11 brake fluid (GM part 12377967 or 992667 Canadian) or its equivalent dot-3 into the reservoir up to its halfway mark using a clean sealed brake fluid container while making sure both hose ends touch the fluid. Press and let go the primary Piston using a round-ended smooth tool for about 25 mm (1 inch) multiple times while observing the fluid exit from the ports. As primary and secondary pistons accept less air during the procedure their travel distance decreases and operation becomes more challenging. Press the primary Piston multiple times so fluid flows easily out of the ports without air bubbles. Follow these steps afterward: (1) take out the transparent hoses from the reservoir, (2) set back the master cylinder reservoir cap and diaphragm, and then (3) detach the fittings with the hoses from the ports while securing the master cylinder with cloth cover to catch spills before extracting it from the vise.