1970+ Ford Disc Brake Pressure Differential and Control Valve Kit


A Muscle Car Research Exclusive!

Muscle Car Research is proud to offer a rebuild kit for the early 1970s Ford disc brake combination pressure differential and rear brake pressure control valve made by Kelsey-Hayes and Wagner. This kit is known to work for the following combination valves:

  • D0OZ-2B257-C (marked D0OA-2B328-D or D2ZA-2B328-AA)
  • D0AZ-2B257-C (marked D0AA-2B328-C)
  • D4FZ-2B257-A (marked D4ZA-2B328-AA)
  • D5ZZ-2B257-A (marked D5ZA-2B328-BA or D5ZA-2B328-BB)
  • D6FZ-2B257-B (marked D6EA-2B328-BA)

Our kit contains all of the parts needed to rebuild your leaky valve and return it to "like new" operating condition, including:

  • O-rings
  • X-ring
  • Proportioning valve seals
  • Proportioning valve spring
  • Copper crush washer

The contents of the kit can be seen compared to the original parts (the new parts included in the kit are underneath the original parts) in the picture above.  All of the rubber parts are molded from a 70 durometer ethylene propylene diene monomer (EPDM) rubber compound that is fully compatible with automobile brake fluid.  The spring is made from type 302 stainless steel and features squared and ground ends.  All parts are made right here in the USA! Are you unsure if this kit is for you?  These valves were originally used on the following Ford and Lincoln/Mercury vehicles equipped with front disc brakes:

  • 1970, 1971, 1972, 1973 Ford Mustang
  • 1970, 1971, 1972, 1973 Mercury Cougar
  • 1970, 1971 Ford Torino
  • 1970 Ford Fairlane
  • 1970, 1971 Mercury Comet
  • 1970, 1971 Mercury Montego
  • 1972 and 1974 Ford Pinto station wagon
  • 1975 Ford Mustang
  • 1975 Ford Granada
  • 1975 Ford Pinto sedan
  • 1976, 1977 Ford Maverick

Complete rebuild instructions are available from the Muscle Car Research web site. Dealer inquiries are welcome - please contact us for pricing. Be sure to check out our Pressure Differential Switch Lock Tool that you can use to keep the piston centered when bleeding your brakes after rebuilding your valve!