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  • #16
    Whoever did your disc brake conversion only did half the job. You need a modern booster and dual master cylinder. That master cylinder is not designed for disc brakes.

    John
    John Pizzi - Squarebirds Administrator

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

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

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    • #17
      I believe that too. However it was working well, only problem being that heated fluid do not expand in the master cylinder.
      Now what do I need and where can I get the parts?

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      • #18
        Hi Eric....the way your system is set up is quite unsafe....there is no way to control the pressure difference needed between the front discs and rear drum brakes....the drum brakes will lock up at around 600 psi and the discs at around 1000-1200 psi...IMG_2823.JPGIMG_2822.JPGIMG_2981.JPG Without a combination valve to control/limit/separate the pressures as required, the rear drums will lock first, before the front discs .. and..if in wet conditions, or panic...you will swap ends in your car before you know it. I am sure more knowledgeable guys here can tell you more ways this system you are using is unsafe... You should google combination valve, disc drum operation for a more in depth explanation..You can contact, Thunderbird Headquarters, The Birdnest, or Eklers to get the stuff you need...There are many posts here, at Squarebirds to help you get the right stuff .These pix show a kit I bought from Thunderbird Headquarters, with the combo valve I custom mntd below the M/Cyl.{and brake light switch in the rear brk line.}
        The 59 requires a special booster brkt/mechanism to lift booster and master cyl for
        clearance on the A/C plenum and rocker cover. CHEERS TERRY
        Last edited by BEVS BIRD; September 23rd, 2019, 03:10 AM.

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        • #19
          Eric, you are a Paid Member. The information regarding the proper set up of a front disc system is in the Members Forum. Check it out. A combination valve is a must to have installed because it controls the brake pressure between the front disc brakes and the rear drum brakes. Here is an explanation of what a combination valve does.

          The OEM combination valve has the PROPORTIONING function, a front brake METERING function, LEAK ISOLATION function, and INDICATION functions. The INDICATOR SWITCH is connected to a hydraulic system that senses pressure loss in either circuit (front and rear are plumbed separately) and isolates that circuit from the other circuit. This enables the 'good' circuit to remain functioning and prevents the total loss of brakes in the event of a leak. This valve is, plumb it and forget it.

          Here are three pix of what a combination valve looks like... 2 are GM style, and 1 is a ford style version...


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

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

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          • #20
            I understand the problems. Even though it works most of the time it will be a problem in an emergency brake.
            I guess was expecting that kind of explanation.

            Ray are you talking about the TCL? I checked there and there is much more than I need. Most of the work has been done already and I "only" have to change the master cylinder and the booster.
            Those nice condition parts will be used on my other 60 which still plays on his drums although I still don't understand what made the brakes lock and why I don't have the 2nd port opened in the master cylinder...
            I checked with Bird Nest on their web site and was not able to find the parts I need.?

            Ray you're talking OEM combination. Do you mean there the Original Equipment Manufacturer's part or the replacement parts I am looking for? I doubt the original parts has all those functions you list!?

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            • #21
              I found those at Thundeebrids Headquarter. Is the first picture, Adjustable Disc Brake Proportioning Valve could be enough?
              Nothing visible on Bird Nest. I may have to call them.
              Attached Files

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              • #22
                I assume you meant to type TRL instead of TCL.. Yes, the TRL has information in it, but I was talking about the Members Conference which is only viewable by those of us who are Paid Members, as you are... Go down to that sub-Forum, below the For Sale/Parts Wanted Forum, and then go to the Members Only thread and read through it. The Combination/Proportioning valve you need is a PV-2, https://www.summitracing.com/parts/clp-pv-2. It is a universal/GM valve that many of us used on our front Disc/Rear Drums conversion. Or you can get and use the Ford version. It is NOT OEM equipment, but aftermarket equipment like much of the Disc Brake Conversion is. If you have just a single bore Master Cylinder, you should get a 1" Bore Corvette Style Dual Master Cylinder - MBM MC1321A. One that controls the front disc brakes and the other the rear drum brakes. With a single MC, you risk brake failure if that single MC ever fails on you. With the Dual MC, if just one side of it fails, you still have the other set of brakes to stop the car. You will have to run brake lines from your dual MC to the Combination/Proportioning Valve, and then to the front and rear brakes. As has already been said, you MUST have that valve in place for proper operation of that disc/drum combination. Some have installed it on the inside fender well. Others down below the dual MC/Dual 8" Power Booster. You might want to get the version with the flat cover on in instead of the dual bubble cover. I used the dual bubble cover and the retaining clips were hitting the inside of my hood when I closed it. I had to adjust my dual MC/Dual 8"Power Booster down a bit to clear it. The 8" Power Booster many of us used is this one. 8" 2 Stage Power Booster MBM PB8537, which looks like the one in your picture, as does the MBM Dual MC.

                BTW, Pirate Jack has many of the components needed when one does this disc/drum brake conversion. https://www.piratejack.net
                Last edited by YellowRose; September 23rd, 2019, 09:07 AM.

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

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

                Comment


                • #23
                  Many of our members have used the booster/MC combo from ABS brakes. The part number is 9787.
                  http://www.abspowerbrake.com/maincat...ameset014.html

                  John
                  Last edited by jopizz; September 23rd, 2019, 11:26 AM.
                  John Pizzi - Squarebirds Administrator

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

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

                  Comment


                  • #24
                    So I'd need a separate proportioning valve? But then why do I have to use a different MC.
                    I guess I am totally lost, I will have to place a few phone calls.

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                    • #25
                      You need to totally isolate the front brakes from the rear brakes for both performance and safety. You can't do that with a single master cylinder.

                      John
                      John Pizzi - Squarebirds Administrator

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

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

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                      • #26
                        Ray, yes TRL

                        OK I called Larry's, TBird HQ, ABS, MBM, PST and Pirate Jack
                        T-Bird HQ has one 58/60 Thunderbird Power Brake Booster/ Dual Master Cylinder KIt for 450$ and 2-3 weeks minimum delivery time.
                        Other brake specialists probably carry the parts but they are not aware they might fit.

                        I was actually trying to find a one stop shop that could supply all the parts I missed but it does not seem to work.
                        So I went to the "hidden" list (Ray let me know if this is OK to talk about it here).
                        But this list is pretty complete and I don't need everything. However I don't want to miss anything either.
                        Anybody would be nice to shorten the list to what I need and forward it to me. I have disc brakes installed so I would need everything from the brake pedal to the wheel cylinders....
                        I guess I can still use some of the copper lines.
                        I'd prefer loosing a couple of days than having to place a new order for some missing bits later...

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                        • #27
                          Do you have factory AC? It makes a difference. The ABS booster has the correct offset bracket to clear the evaporator housing. The TB Headquarters booster combo looks similar. I don't know if the MBM booster has the correct bracket. You also need the proportioning valve. ABS has the valve with the mounting bracket and the lines to the master cylinder already formed. It doesn't appear that TB headquarters has that. You will need to fabricate the other lines that go to the rear brakes and the front calipers. They are not available in any catalog.

                          John
                          John Pizzi - Squarebirds Administrator

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

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

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                          • #28
                            No, non Air Conditionned on this car.
                            Can't I use or alter the existing lines?
                            Last edited by Eric S; September 24th, 2019, 07:37 AM.

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                            • #29
                              Right now you only have one line coming from the master cylinder down to the block where it branches off. You will need two separate lines coming off the prop valve. You can probably reuse the single line, the connecting block and the lines going to the front calipers. You will have to fabricate at least one line from the prop valve to connect to the long line that goes to the rear. You will have to remove it from the connecting block and either block off the port or use it for the brake light switch.

                              John
                              John Pizzi - Squarebirds Administrator

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

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

                              Comment


                              • #30
                                Originally posted by Eric S View Post
                                ...Can't I use or alter the existing lines?
                                The only line you can reuse is from the union (just forward of the driver's door) to the rear wheels. But, WHY? If you're going to plumb your brake system, don't bet on steel lines that are 60 years old. New brake line is cheap insurance.

                                Mount all your devices then plumb your lines to them. Do it all at once so you don't have to do it over and over. Plumbing your car can be done at home on a Saturday morning.


                                - Dave
                                My latest project:
                                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

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