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disc coversion k/H under dash puzziled

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  • elvis
    Apprentice
    • Mar 31 2011
    • 45

    disc coversion k/H under dash puzziled

    Hello you guys
    6 month ago before I registered in this marvelous forum I started to modify the front brakes now reading you guys Im really asking myself if Im on de right track my set up include granada spindle,disc, caliper, master cylinder, and proportioning valve .
    where im not sure is I was planning to use my original power booster under the dash what I did is modify the original push rod with an ajustable round tip and was planning to bolt the master cylinder directly on the fire wall and using the original set up to activate the granada master cylinder. crazy or might work . please how can I post picture
    " go for your dreams "
    Yves as Elvissigpic
  • YellowRose
    Super-Experienced


    • Jan 21 2008
    • 17191

    #2
    disc coversion k/H under dash puzziled

    I am going to let someone, like Howard Prout, or others who have done this conversion answer your questions. I know that Howard left his KH under dash unit in place and is using it, and I plan on doing the same thing.

    Regarding posting pictures on our Forum server, that is something that is a benefit that only Paid Members receive, along with several other benefits. If one wants to become a Paid Member, and has a PayPal account, you can do so by clicking on the Donate to Site button at the top right of this Forum. It will take you through the process. If one does not want to be a Paid Member, you can either send me the pictures and I will post them for you. Or you can go to any free picture hosting website, like Photobucket, create an account with them, upload your pictures, and then post the link to them in our Forum for the other members to see.

    Ray Clark - Squarebirds Administrator
    The Terminator..... VTCI #11178 ITC #6000 Yellow Mustang Registry (YMR) #12188
    Contact me via Private Message for my email address, or Call (Cell) 210-875-1411

    https://www.squarebirds.org/picture_gallery/TechnicalResourceLibrary/trl.htm
    Faye's Ovarian Cancer Memorial Website.
    https://faye.rayclark.info/index.html

    Comment

    • simplyconnected
      Administrator
      • May 26 2009
      • 8779

      #3
      You're on the right track, but there are a few variables in your setup.

      I don't know if the bolt pattern on a Granada M/C will fit your firewall pattern.

      Back in the day, yes, Squarebirds had PB's but they were drum brakes. Drum brakes require hundreds of psi LESS than disks. That means the power booster you already have will probably only offer a small assist. In my opinion, you need more; at least an 8" dual-diaphragm booster.

      There is no real reason to take your treadle vac unit out because it is attached to the pedal and divorced from the M/C.

      If you go with another booster on the engine side of the firewall, you need a bracket that raises the booster/master combination a few inches, and a longer pushrod from the pedal. A new bracket can have slotted holes to accommodate any bolt pattern. Here is an OEM booster/bracket from 1960:







      The bracket is VERY hard to come by, so Howard made his own. We can get a chromed booster and M/C for about US$200 + s/h.

      I hope this helps.

      Hey all you die makers... how can we make this bracket? It needs to be stamped for consistancy. We can lay out and drill holes in the same place. - Dave
      Last edited by simplyconnected; April 9, 2011, 01:49 PM.
      Member, Sons of the American Revolution

      CLICK HERE to see my custom hydraulic roller 390 FE build.

      "We've got to pause and ask ourselves: How much clean air do we need?"
      --Lee Iacocca

      From: Royal Oak, Michigan

      Comment

      • Howard Prout
        Experienced
        • Feb 11 2009
        • 443

        #4
        As Dave and Ray said, I couldn't find appropriate brackets for mounting the new booser and MC so made my own. The attached pix shows the new assembly. The old MC is simply as a jig for the bolt pattern through the firewall. The bottom line is that the booster had to be raised 5" to clear the valve cover and out 5" from the firewall to provide enough room for the pivot arm. One of the unexpected issues I came across was getting the top of the pivot arm out far enough to prevent interference with the firewall. I ended up having to put spacer plates between the firewall and the new booster bracket. In the next design iteration I would make the brackets 1/4" deeper. BTW, notice that the bottom ends of the brackets are piched closer together - that is to prevent interference with the steering column. The development of these brackets is discussed in greater depth in the "Disc Brake Converison" thread.
        Attached Files
        Last edited by Howard Prout; April 9, 2011, 06:51 PM. Reason: additions
        sigpic "Old Betsy" - my '59 convertible J9YJ116209 Thunderbird Registry #33341

        Comment

        • DKheld
          Super-Experienced
          • Aug 27 2008
          • 1583

          #5
          Guess my setup is closest to yours - I have the Granada spindles, rotors and calipers. Master Power (generic) combo valve and a Lincoln master cyl.

          Looked on Advance Auto site for a 75 Linc vs 75 Granada master cyl. Both have only 2 bolts - the original Tbird master had 4 bolts both A/C and non A/C cars according to the service manual. The 10-1602 Granada master is taller than the 10-1603 Lincoln master - otherwise they looked the same - they don't give specs on pressures on the Advance site. Looked at the service manual and it appears you could remove one set of the smaller studs (lower) and install larger longer bolts through the firewall to bolt the new 2 stud style Granada master cyl on. This is a big - no huge - assumption that they will allow the master cyl and booster to line up but every now and then someone wins the lottery.

          On the booster. I had mine modified to accept the 2 stud style master cyl - done - no other modifications needed - well - you do have to round off the master cyl push rod to fit better in the Lincoln master cyl. but all the pedal stuff stays stock. Mine is the style mounted on the outside firewall (see below).

          If you have the A/C box on the firewall you won't be able to add a standard Tbird non A/C style booster on the firewall - it is 1 3/4 inch too close and will need to be moved out plus a 1 3/4 inch longer pedal rod installed. There was a factory/dealer kit to do this but in 10 years of looking I have only "heard" of one person having one. The dual action system that Dave and Howard fabricated may clear the A/C box.

          Looking at the manual (pg 10-21) there is a tricky pedal trigger adjustment for the under the dash booster setup that may give you trouble on your Granada master setup but if you keep adjusting.....maybe.

          My booster (on the outside firewall) seems to provide plenty of boost for the Lincoln/ Granada setup - the pedal feels about the same as it did with dual drums but stops like it has discs.

          Good luck and let us know how it goes.....

          Eric
          registry 5347

          posting pics.
          I upload my pics to a free site (Dropshots) and there are a few others. Find the pic you want to post on the host site like Dropshots and bring up the full size version of your picture. right click on the pic and view the info where you will find the path to the pic. (something like this http://www.dropshots.com/DKHeld#albu...07-12/20:01:15)
          Back on Squarebirds post just above where you are posting your message there is a yellow button with mountains (guess that's supposed to be a pic). Click on the button to add a pic and it will ask for the URL to the picture. Copy and paste the path you found on your picture host site and it will appear in your post.




          Comment

          • YellowRose
            Super-Experienced


            • Jan 21 2008
            • 17191

            #6
            disc coversion k/H under dash puzziled

            Thanks for the information on how you did your conversion, Eric! I will be doing the same conversion to front disc brakes and a dual MC/dual power booster that Howard recently did. I am using the same parts, the same chromed dual MC/dual power booster, same firewall mounting bracket he had made for me that he used on his, same calipers, rims, pads, you name it. Mine is an exact duplicate of his system which is working well for him. The firewall mounting bracket that he made DOES clear the AC plenum, his valve cover and the power steering system. Not by a whole lot, I gather, but it does clear it all. I hope to be able to take step by step pictures during my conversion process and put up a step by step account of how to do it. IF the company that is going to do it for me, will allow me to do so. Howard was going to do that, but the guy who did his had a lot of the work done before he could put a camera to it and he was not able to get the pictures. Howards equipment that he used all works and without worries about whether or not you can get your front end to align correctly, unlike some other kits out there.

            BTW, elvis will be able to upload his own pix right to our server. He became a Paid Member today! Thank you, Sir! Anyone can become a Paid Member by having a PayPal account and go to the Donate to Site button at the top right of this Forum.

            Ray Clark - Squarebirds Administrator
            The Terminator..... VTCI #11178 ITC #6000 Yellow Mustang Registry (YMR) #12188
            Contact me via Private Message for my email address, or Call (Cell) 210-875-1411

            https://www.squarebirds.org/picture_gallery/TechnicalResourceLibrary/trl.htm
            Faye's Ovarian Cancer Memorial Website.
            https://faye.rayclark.info/index.html

            Comment

            • ncbird
              Experienced
              • Jan 5 2008
              • 390

              #7
              Ditto Eric

              My setup is going to be similar to Erics and Eric has the most experience with this setup. If you don't have a factory A/C car the factory bracket with modified booster is simple and easy. My setup will be Versailles spindles (same as Granada with large lower ball joint), Lincoln MC for disc/disc, Versailles combo valve. Booster Dewey will take your booster/bracket and convert it to take the granada/lincoln mc and test both together for around $200.00. You can probably get a core from Carl Heller (partsetal on this site) at a reasonable price. As Dave says you must have a booster to go to disc brakes. The stock pedal gives you a 6x1 conversion meaning you press with 100lbs and it gives 600lbs at the MC. You must have greater then 1000 lbs for disc brakes. It is my belief in studying the Versailles/Granada spindle that you need to use the outer tie rod ends from the Granada. The steering arm sits lower then the stock bird and the tie rod ends minimize this. The stock tie rod ends put the line of the tie rod below the steering arm where the V/G tie rod ends line the tie rod up with the center of the steering arm. This 3/4 of an inch may not seem like much but could minimize any bump steer tendencies.
              Just my shade tree opinion since no engineers were sacrificed in my work. Grant
              Last edited by ncbird; April 10, 2011, 06:02 AM.
              Grant
              NCbird on the Coast of NC
              "Dads Bird" for my father

              Comment

              • elvis
                Apprentice
                • Mar 31 2011
                • 45

                #8
                thank you

                thank you guys for the reply I'll keep you informe
                " go for your dreams "
                Yves as Elvissigpic

                Comment

                • jacob80
                  Newbie
                  • Jun 10 2015
                  • 12

                  #9
                  Hopefully I'm not hijacking this thread, but I have a similar situation...

                  I am using the SSBC A152 kit on a 1959 Thunderbird. After the whole kit was installed, I realized there is a booster under the dash (which I have NEVER seen before!). After bleeding everything, as mentioned before, the booster is not adequate to push these disk brake pistons and no matter what I do, the pedal is extremely soft.

                  The kit shows it is for non-power brakes cars, so should I somehow get rid of the under dash booster or do something similar to what has been discussed in this thread?

                  SSBC A152: http://ssbrakes.com/i-10092475-disc-...tors-a152.html

                  Comment

                  • jopizz
                    Super-Experienced


                    • Nov 23 2009
                    • 8317

                    #10
                    I've never heard of a disc brake system that didn't need a modern booster. Whether or not you have the under dash booster I don't see how it's possible to generate enough power to get the calipers to stop safely. If there was a system that worked without a booster don't you think modern car manufacturers would use it to save money. Like they say if it sounds too good to be true then it probably is.

                    John
                    John Pizzi - Squarebirds Administrator

                    Thunderbird Registry #36223
                    jopizz@squarebirds.org 856-779-9695

                    https://www.squarebirds.org/picture_gallery/TechnicalResourceLibrary/trl.htm

                    Comment

                    • YellowRose
                      Super-Experienced


                      • Jan 21 2008
                      • 17191

                      #11
                      disc coversion k/H under dash puzziled

                      Both myself and Howard Prout have the KH under dash booster in our Squarebirds. We did NOT take it out when we did our front disc brake conversion. We just left it in place as it was. Looking at the kit you referenced, I also do not see a dual 8" Power Booster with that kit. IF your car has OEM AC on it, you are gonna have to come up with a mounting bracket that will get that booster/MC past the AC plenum box. You will probably have to make a bracket if you have AC.

                      Ray Clark - Squarebirds Administrator
                      The Terminator..... VTCI #11178 ITC #6000 Yellow Mustang Registry (YMR) #12188
                      Contact me via Private Message for my email address, or Call (Cell) 210-875-1411

                      https://www.squarebirds.org/picture_gallery/TechnicalResourceLibrary/trl.htm
                      Faye's Ovarian Cancer Memorial Website.
                      https://faye.rayclark.info/index.html

                      Comment

                      • DKheld
                        Super-Experienced
                        • Aug 27 2008
                        • 1583

                        #12
                        They should work without the booster. I've had lots of British cars with manual front disc brakes.

                        If the car is not running (producing vacuum assist to the booster) and the pedal is still soft there is still air in the system.

                        Just a reference guess but if it takes 100lbs of pressure on the pedal to stop the car without the booster it should take less pressure (on the pedal) with the "booster assistance". The under dash booster will help but probably won't provide enough boost to make the system feel like a modern disc brake setup. I have the original Bendix booster (modified to accept a new style master cyl) under the hood and it works fine - probably requires more pedal pressure than the new dual boosters but I like mine as is.

                        The pic in that link doesn't show a proportioning valve only an adjustable rear residual valve. I'm guessing you did you re-plumb the system and split it by taking out the junction on the frame? Needs to be separate systems front and back now with the addition of front discs.

                        Eric

                        Comment

                        • YellowRose
                          Super-Experienced


                          • Jan 21 2008
                          • 17191

                          #13
                          disc coversion k/H under dash puzziled

                          Every time I log onto this Forum, I learn something new! Thanks for posting that information, Eric! I thought one had to have the booster for that complete system to work properly. Apparently, it is better if you have it, but it will work without it...

                          Ray Clark - Squarebirds Administrator
                          The Terminator..... VTCI #11178 ITC #6000 Yellow Mustang Registry (YMR) #12188
                          Contact me via Private Message for my email address, or Call (Cell) 210-875-1411

                          https://www.squarebirds.org/picture_gallery/TechnicalResourceLibrary/trl.htm
                          Faye's Ovarian Cancer Memorial Website.
                          https://faye.rayclark.info/index.html

                          Comment

                          • DKheld
                            Super-Experienced
                            • Aug 27 2008
                            • 1583

                            #14
                            No problem Ray - difference is though the British cars were designed not to have a booster so the pedal ratio etc is I'm sure different (as well as weighing 1/2 as much).

                            Can't imagine how much pressure you would need to stop these 2 ton Birds without a booster. Don't think it would be very comfortable to drive (or stop).

                            Eric

                            Just for fun......

                            Current resto with non power front discs


                            close up of the front discs



                            And I converted this one from front drums to front discs while restoring.

                            Comment

                            • jopizz
                              Super-Experienced


                              • Nov 23 2009
                              • 8317

                              #15
                              "Working" is a relative term. You can also stop a car with your feet but I wouldn't want to try it. Should work and does work are two different things. I can't wait until Dave sees this. Let the fireworks begin.

                              John
                              John Pizzi - Squarebirds Administrator

                              Thunderbird Registry #36223
                              jopizz@squarebirds.org 856-779-9695

                              https://www.squarebirds.org/picture_gallery/TechnicalResourceLibrary/trl.htm

                              Comment

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