When faced with a leaking brake valve, many adventurous home mechanics follow the same path I did and wonder if it's possible to rebuild the valve. Many valves can indeed be rebuilt, but it's important to understand that it can't usually be done using seals found at your local parts store. That's because the Nitrile/Buna-N or Viton (a fluoroelastomer) rubber compounds used in o-rings and other seals found in "over the counter" kits aren't compatible with automotive brake fluid - they're designed to be compatible with petroleum-based fluids like engine oil and gasoline!

This brake pressure proportioning valve (Ford calls it a "brake pressure reducing valve") was removed from a 1997 Ford Thunderbird. It is marked "F6SC2B091CA"; the service part number is F6SZ-2B091-CA. Original applications include the 1996 and 1997 Ford Thunderbird and Mercury Cougar. You can click on the pictures below to see larger versions of the images.