2005 Buick LeSabre Brake Master Cylinder Reservoir

You should inspect the reservoir for cracks or deformities. If found, replace the reservoir, clean the reservoir with clean denatured alcohol, or equivalent, dry the reservoir with non-lubricated, filtered air, lubricate the new seals and the reservoir bayonets with new Delco Supreme 11 GM P/N 12377967 (Canadian P/N 992667) or equivalent DOT-3 brake fluid, install the seals, making sure they are fully seated, install the reservoir onto the master cylinder by pressing straight down by hand until pin holes are aligned, tap in the reservoir retaining pins to secure the reservoir, fill the master cylinder reservoir, install the brake fluid level sensor and install the master cylinder to the vehicle.