Refer to

Caution: Brake fluid may be irritating to the skin or eyes. In case of contact, take the following actions:

Notice: Do not use fluid that has a petroleum base. Do not use a container that has been used for petroleum based fluids or is wet with water. Petroleum-based fluids cause swelling and distortion of rubber parts in the hydraulic brake system and water lowers the brake fluid's boiling point. Keep all fluid containers capped to prevent contamination.

Thoroughly clean the master cylinder cover before removal. This prevents dirt from entering the reservoirs.

1. Remove the cover and the diaphragm.
2. Add brake fluid in order to fill the reservoirs to the full mark. Use Delco Supreme No. 11 Hydraulic Brake Fluid (GM P/N 1052535) or an equivalent DOT 3 motor vehicle brake fluid.