Re: Brakes Problem
This is directly from GM service information.
NOTICE: Power steering fluid, engine oil, brake fluid, or any other mineral based fluids cannot be mixed. If brake seals contact power steering fluid, or steering seals contact brake fluid, seal damage will result.
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.
This information is from an 08 vehicle. Contaminated fluid in the brake system can and will destroy the rubber components, i have seen it happen on many occasions, no matter if they are old or modern. Some of the compounds in the seals may be the same, yes, but all seals and hoses are made with certain properties specially formulated for whatever fluids they will be used with. Some can be interchanged even, but when it comes to brake fluid... no.
NEVER argue with a stupid person. They bring you down to their level, and then beat you with experience.