Disc brake conversion master cylinder question.

Brakes for your Classic Mopar

  1. DusterJoe410.4

    DusterJoe410.4 Active Member

    Messages:
    27
    Likes Received:
    4
    Joined:
    Jan 17, 2019
    Location:
    Northwest Ohio
    Local Time:
    12:53 PM
    I’m converting my 71 Duster to 73-^ BBP disc brakes and 11” BBP drum rear brakes. The car will have manual brakes, and I’m trying to determine what master cylinder I need. I have a leftover new unused DBMC10 from Right Stuff, it lists as a 1.063 bore size. It was bought for a power brake 73 340 Duster we built. I was under the impression that power vs manual masters were different but recently found some saying they used the same master on a manual brake car. Am I correct or will it work for my application? Thanks for any help you can give.

    49E13C80-3AD0-449D-B485-DAF89119494C.jpeg

    070EE86D-79B7-45ED-A359-68B49329EA27.jpeg

    8C9375A1-329C-445C-90AC-4C7FDE9805C1.jpeg
     
  2. RedFish

    RedFish Well-Known Member

    Messages:
    23,341
    Likes Received:
    2191
    Joined:
    Sep 5, 2007
    Local Time:
    11:53 AM
    Since that is a new aftermarket part... first is to check that its piston was machined for the manual brake pedal rods rubber retainer. We can't take anything for granted.
    Do your 11 inch drum brakes have larger bore wheel cylinders than standard 10 inch brakes? That master cylinder bore might be about right. I have used the info/specs shown at rockauto to sort the differences.
     
    • Like Like x 1
    • 72bluNblu

      72bluNblu FABO Gold Member FABO Gold Member

      Messages:
      9,485
      Likes Received:
      3625
      Joined:
      Nov 28, 2008
      Location:
      NorCal
      Local Time:
      9:53 AM
      That master cylinder will give you a high, hard pedal with those brakes. It will work and some people do like that pedal feel, but I’m not one of them. I run 15/16” master cylinders on my manual disk/drum cars, and I also run the larger 11” rear drums. The 15/16” master cylinder gives a slightly softer pedal with a little more travel. It makes it easier to feel the friction point on the brakes and makes things a little easier on your leg too.
       
      Last edited: Feb 11, 2019
      • Like Like x 1
      • Agree Agree x 1
      • DusterJoe410.4

        DusterJoe410.4 Active Member

        Messages:
        27
        Likes Received:
        4
        Joined:
        Jan 17, 2019
        Location:
        Northwest Ohio
        Local Time:
        12:53 PM
        Thanks for the info guys! Now I know what I need to look for. I have this master posted in the for trade section if anyone has a 15/16” one in the same condition they would like to trade.
         
      • 72Dart6pack

        72Dart6pack Harder Better Faster Stronger.

        Messages:
        3,008
        Likes Received:
        2062
        Joined:
        Feb 1, 2016
        Location:
        Roseville Michigan
        Local Time:
        12:53 PM
        Go 15/16
        Bet we can drag this post out to 45 responses. And still not have a answer.
         
        • Agree Agree x 4
        1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
          By continuing to use this site, you are consenting to our use of cookies.