GM Service Manual Online
For 1990-2009 cars only

Notice: When filling the master cylinder, use only Delco Supreme 11, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT 3 brake fluid. Do not use a container which has been used for petroleum based fluids, or a container which is wet with water. Petroleum based fluids will cause swelling and distortion of rubber parts in the hydraulic brake system, and water will mix with brake fluid, lowering the boiling point. Keep all fluid containers capped to prevent contamination.

Keep the master cylinder reservoir properly filled in order to ensure adequate reserve, and to prevent air and moisture from entering the hydraulic system. However, because of expansion due to heat absorbed from the brakes and the engine, do not overfill the reservoir. Do not add fluid if the brake hydraulic system is not leaking.

The master cylinder reservoir is part of the master cylinder assembly, which is located under the hood on the drivers side of the vehicle.

  1. Thoroughly clean the master cylinder reservoir cover before removal in order to avoid getting dirt into reservoir.
  2. Remove the cover and the diaphragm and add fluid as required to bring level to 20-26 mm (0.78-1.0 in) below the filler neck inside the reservoir.