Inspect the reservoir for cracks or deformation. If found, replace the reservoir.
Clean the reservoir with denatured alcohol, or equivalent.
Dry the reservoir with non-lubricated, filtered air.
Lubricate the new seals and the outer surface area of the reservoir-to-housing barrels with Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667) or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
Install the lubricated seals. Ensure that they are fully seated.
Install the reservoir to the master cylinder by pressing the reservoir straight down on the master cylinder until the pin holes are aligned.
Carefully install the reservoir retaining pins to secure the reservoir.
Place the brake fluid level sensor into the reservoir, press into place to secure the sensor retaining tabs, if applicable.