which master cylinder?

Brakes for your Classic Mopar

  1. roadrr

    roadrr Member

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    so ive been digging through post to no avail! i see where people ask which master cylinder for a 1970 duster 340 with front manual disk and manual rear drum and get recommedations but nothing definate on what was used, so again what master cylinder is a good replacement that people have used and works. with part numbers if possilble and where purchased please, anybody
    ??
     
  2. Fast340cuda

    Fast340cuda Well-Known Member

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    I used one from a 1973 Dodge Dart (disc version) on my 68 barracuda with factory front disc (same as your application).

    I would check Rockauto for part number reference from the various manufacturers then buy one off of eBay or Amazon.
     
  3. mvh

    mvh FABO Gold Member FABO Gold Member

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    The problem is that the brake part manufacturer application listings for A-body disc brakes are thoroughly screwed up. In theory, there should be two 1967-72 disc brake master cylinders: one for Manual with a 1-1/32" bore, and one for Power with a 15/16" bore (otherwise interchangeable). But you will find a lot more variations in part numbers than just those two, and some of the listed items will actually be drum brake masters. Annoyingly, most store sites don't give the bore dimension, but you can Google the part number and find a manufacturer listing that will show it (Cardone or Bendix, for example). That said, it is frequently recommended that you use the Power master cylinder for Manual disc brakes — the smaller bore reduces the pedal effort while slightly increasing the pedal travel — most people today seem to find that a reasonable trade off. I have one car with each, and I can tell you that the 15/16 bore MC feels plenty hard — the 1-1/32 bore feels like you need both feet (great for threshold braking at the track, but startling if you step into it from a modern vehicle). There are also other versions of the same basic master cylinder with other bore sizes — 1" is common on B-bodies, and 1-1/8 is also encountered. So I don't trust the application listings — I research the specs for the part shown to ensure it has the bore I want.
     
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    • Dartsun

      Dartsun Mopar Dude

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      For my kelsey hayes manual front disc 10” rear drums I went with this master cylinder. So far so good been a few years now.
      9D27EB60-F221-4115-95BD-91436E5A65DC.png
       
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      • Joey4speed

        Joey4speed FABO Gold Member FABO Gold Member

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        Google
        MOPAR MASTER CYLINDER GUIDE BY THE RAM MAN.
        These 5 pages explains it all, great if you want the correct
        look that works.
        Also see thread from September:
        WHAT MASTER CYLINDER ?
         
      • mrhp

        mrhp Well-Known Member

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        This is a good thread too: upgrade master brake cylinder

        To my knowledge, there are no exact rebuilt replacements available and there is no kit available (The one from Dorman is for drum/drum).

        The later '73 on up style iron 15/16" bore ones will work fine however they are larger in size. The 15/16" DoctorDiff, while looking more modern, is a welcome 'no leak' style.

        I recently did the DoctorDiff. Until my stock one started to go bad, it was a very hard pedal. The DoctorDiff is definitely an improvement.

        upload_2020-12-22_19-46-47.png
         
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        • 70chall440

          70chall440 Mopar or No Car...

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          My information shows PN 2808600 casting no 2225411 for 67-70 A body, 1" bore diameter.
           
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          • inertia

            inertia Well-Known Member

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            This is a new 15/16 m/c.
            Straight bolt on, no fuss, no mess, no adapters.
            This is prefered by most spirited drivers for it's feel and modulation, while maintaining the "original" look . .

            More Information for RAYBESTOS MC36406
             
            Last edited: Dec 24, 2020
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            • roccodart440

              roccodart440 Well-Known Member

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              I run a 7/8 on my manual brake setup
               
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              • famous bob

                famous bob mopar misfit

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                Wish I`d gone 7/8 , installed 15/16 on my 4 wheel manual disc setup ..

                What brand 7/8 ----??
                 
              • roccodart440

                roccodart440 Well-Known Member

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                Wilwood
                 
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                • BillGrissom

                  BillGrissom Well-Known Member

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                  An inexpensive 7/8" bore MC which works is for a 1995-99 "cloud car" (Breeze, Stratus, Cirrus) w/ ABS (2 ports). You will need a 2 to 4 bolt adapter plate ($30 ebay). I have one on my 1964 Valiant (manual), 1965 Dart (w/ Intrepid booster on Dart firewall brackets, see profile photo), and 1965 Newport (2-4 adapter to factory booster). Search for my post w/ photo showing that the pedal winds up in the same place w/ the Breeze MC on adapter plate as the factory manual MC. I have a new MC w/ reservoir on the shelf now as a spare for all 3 cars, which might have cost $25 on ebay.

                  I expect something from the GM or Ford racks might also work. I just grabbed something newish from the Mopar rows while at PicNPull years ago. If you go with a 2000+ MC, you run into bubble-flare fittings, which you can form with an old dbl-flare tool (youtube), but why bother.
                   
                • Jet

                  Jet Well-Known Member

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                  Dorman M39736
                   
                • 1969moparDART

                  1969moparDART Well-Known Member

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                  do you have a link to the one you got from dr diff?
                   
                • mrhp

                  mrhp Well-Known Member

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