Results 1 to 4 of 4
  1. #1
    Join Date
    Bloomington, Indiana
    Liked: 24

    Default Best Girling Master Cylinder size

    Hey gang-Quick question. I have a 1972 Merlyn Mk20AS, I have enjoyed racing it and learning FF after 15 years with the Bugeye, but I have noticed that some items on the car perhaps, should be looked into before just replaced. My example-I need to replace the front brake master cylinder -and it is a Girling, I have not yet checked the bore size, but other than just matching it, (as it could have been replaced with the incorrect size), I wondered if this group would know what the size should be for the front and rear bores of each of these? It appears I have the Girling LF14 calipers front and rear-number DA21768 at each. As I replace the pads with new-should I replace the rotors too-and I assume those are easily done with Triumph Spit MKIV ones?

  2. #2
    Senior Member kea's Avatar
    Join Date
    madison heights,mi
    Liked: 625

    Default Master Cylinder

    Master cylinder size. Smaller front then rear.
    Probably 5/8" bore front, 3/4" bore rear.
    The brake disc may not be a street item.
    Often (not always) those street applications used brake disc that had a smaller OD then what we run on our FF.
    Besides having Girling masters, I also have KFP Magnum brake pads for your application.
    Averill Racing Stuff, Inc.

  3. The following 3 users liked this post:

  4. #3
    Senior Member
    Join Date
    Milan, MI
    Liked: 315


    I highly recommend buy Girling. I have been very disappointed with Wilwood so don’t go cheap.

  5. The following 2 users liked this post:

  6. #4
    Contributing Member Garey Guzman's Avatar
    Join Date
    Murfreesboro, TN
    Liked: 868


    Kieth has the size data and Dave makes a great point about quality.
    I will add that if I am happy with the balance and performance of my systems, which ever one I'm working on, I exchange like for like to keep it the same. If something is changed, it will likely require a fair bit of focused attention to get back in the sweet spot.
    Garey Guzman
    FF #4 (Former Cal Club member, current Atlanta Region member) (includes Zink and Citation Registry) (includes information on the FF Kent engine, chassis and history)

  7. The following members LIKED this post:

Thread Information

Users Browsing this Thread

There are currently 5 users browsing this thread. (0 members and 5 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

About Us
Since 2000, has been the go-to place for amateur road racing enthusiasts, bringing together a friendly community of racers, fans, and industry professionals. We're all about creating a space where people can connect, share knowledge, and exchange parts and vehicles, with a focus on specific race cars, classes, series, and events. Our community includes all major purpose-built road racing classes, like the Sports Car Club of America (SCCA) and various pro series across North America and beyond. At ApexSpeed, we're passionate about amateur motorsports and are dedicated to helping our community have fun and grow while creating lasting memories on and off the track.