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PLEASE RELOAD YOUR AVATAR. You shouldn't have any problems doing this, now. Thanks again for the delay but now it is over. - Dave
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Disk Brake Conversion Discussion

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  • Considering next for year;

    SSBC has a kit (compatable w/my frt disc set up) for rr disc.
    10" rotors and bolt on. According to them, even my M/Cyl will work
    with the adjustable prop valve. Just back it all the way off as opposed
    to all the way up as it is right now.
    Four wheel disc !!! Yeah Baby !!!! She'd stop like a Winston Cup Car w/that !!!! From a safety standpoint I'm really thinking about it.

    I did have to (use) the disc brakes last Sunday. I was on 580 on the other side of the Altamont headed towards the Central Valley (Anyone familiar w/this part of Calif knows the stretch I mean - down hill . . . flow of traffic doin' 80) And it all came to a halt because of a roadside fire (in the center) Had to brake HARD. No problem. Came right down to 10 mph w/room to spare.
    So yeah . . . Can't beat having good brakes.
    John Byers
    1960 Convertible (Orig owner)
    sigpic

    Comment


    • I ran all summer with my converted disc brakes and all went well. However, I was uncomfortable with how close the brake pedal went to the floor. The solution seemed to be to reduce the amount of brake pedal travel. This can be accomplished by increasing the leverage ratio on the pivot arm. The down side of this is that it also increases the amount of foot pressure required for braking. So yesterday I repaced the hockey stick brake push rod with a straight one and connected it to a lower point on the pivot arm. However in the process I also realized that a longer push rod would move the brake pedal to a rest position higher from the floor, so I made a second straight push rod 1/8" longer and installed it. The brake pedal now sits a little higher than the gas pedal and has a comfortable amount of travel. However, it does require more foot pressure than before. I now think another iteration is worth trying - to keep the hockey stick configuration but make it a bit longer.

      As an aside, I am currently using both the KH booster and the new MTM booster. When I was putting things back together, the trigger arm for the KH booster was bent making it inoperative. The brakes were very stiff. I then realized that the KH unit was not working, figured out what the problem was and fixed it, so the KH unit is working again. It makes a big difference. So my suggestion to those planning to do a disc brake conversion is to run both boosters.
      Last edited by Howard Prout; November 16th, 2010, 11:27 AM. Reason: spelling
      sigpic "Old Betsy" - my '59 convertible J9YJ116209 Thunderbird Registry #33341

      Comment


      • I just read this entire thread from start to finish - 5 1/2 hours of making notes! More than 2 years of threading! I'll eventually sort out all the info, but right now I think I'd like to just change my original 1 line MC to a 2 chamber for safety sake. I'm never gonna drive this car more than 75 miles from home, and maybe not even that.
        Can you guys tell me if it's possible to not add another booster if you go to front disc brakes? I think I read somewhere here that i won't have enough leg power to make it work.

        - Dave

        Comment


        • I have rebuilt and used both systems - original drum and Granada disc setup (assuming a 352 non a/c car with the booster in the engine compartment).

          The easiest way (maybe not the least expensive) to change to a dual circuit master cyl is to send the booster off and have the face changed to a newer style with 2 bolts. (Power Brake Booster Exchange - mine cost about $250 but I just bought one outright to keep my old original one) Many dual drum master cyl's are available in the 2 stud style (late 60's Mustang etc) but I don't know of any 4 stud style dual drum master cyls. Using the modified original booster you don't run into all the problems associated with pedal height, different booster pressures, pedal rod length, etc. Nothing is changed from the booster back. The booster face supplied accepts a Lincoln disc/drum master cyl but I bet the folks at Power Brake Booster Exchange would supply a drum/drum master cyl.

          NCbird took an original Tbird booster apart and it looks like you could modify an existing one to accept the 2 stud style master cyl so that would be cheaper and easier than sending off the booster for modification.

          HOWEVER - even if you change to a dual circuit drum master cyl the original Tbird setup has only one line from the master cyl to the brake system so the dual circuit master wouldn't make an difference. If that single master cyl line, any other line or cyl fails the whole system is leaking - pressure goes away and the entire system fails.

          To make it a true dual circuit you would need to separate the front and rear systems. I did that at the junction block on the frame. I ran 2 new lines to the front wheels and used the existing lines and junction block for the rear and brake light.

          Additionally in my disc/drum system I have a combo valve in line that regulated front and rear pressures and has a shuttle valve to shut off the system that fails. (sold many places but got mine from Master Power Brakes - $125)

          This is my system all stock from the face of the booster back and the Granada disc spindles. If I had it all to do over again the only thing I would change is that I would use the scarebird brackets on the original spindles mostly because of alignment issues on the Granada spindles.




          Eric
          registry 5347
          http://www.tbirdregistry.com/ft.asp
          Last edited by DKheld; March 14th, 2011, 09:30 PM.

          Comment


          • Thx Eric,
            I don't have a booster in the engine compartment - I have the accordion style H&K booster under the dash. I will keep that and try to find a dual cylinder MC to replace my single cylinder one. I have the 352 W/O a.c. so no worries room wise. If I do that can I just separate out the front and back lines, and use the larger cylinder for the front end? Does anyone make a dual cylinder MC that is perhaps 70/30 pressure wise?
            I will trace out all existing lines and make sure there is no rust. I will replace all the rubber in the lines, and either rebuild or replace the wheel cylinders. That should make it drivable for the next few years. I'll only be driving it down the street and back to make sure it works. Eventually I'll go to disc front, but that could be 5 or 10 years down the line. This car is going to be a Rat Rod style vehicle. Junkie interior, no paint other than whatever my daughter wants to do with a spray can and her artistic talent. Eventually it'll have a 4 on the floor and a low posi-trac rear end. When ever I start playing with this car I just can't stop! It's so much fun to tear into and see how stuff works.
            My point is, I don't want it to be perfect or original in any way shape or form, just something to do when I'm killing time.
            If you want to see pictures go to my "picasa" link; https://picasaweb.google.com/1014928...zpxazQnbj8uAE#

            thx, Dave

            Comment


            • You can get a dual master for a drum/drum car from NAPA for about 50 bucks. Search on thier website for master cylinders for a "1967 Mustang". Ford Shop Manual lists the m/c bore diameter for a power brake-equiped car as 1-1/8"; and a 1" bore for 'birds without power brakes.

              In regards to the 70/30 question you have below, I think I read somewhere on here (from a member far more knowledgeable than me) that the wheel cylinders on an all-drum car were sized differently so as to already give the proper proportioning front to back.
              http://www.tbirdregistry.com/viewdat...ryNumber=33517

              Comment


              • Thx Dave, I just finished reading your thread about doing yours this way. "getting ready to run the new brakes lines". That's most likely what I'll do for now too. I don't have the money right now to do the disc/drum setup.
                So to clarify; we can keep the front and back lines completely separate from each other and do the plumbing with the front brakes to the firewall side line on the MC - in case we end up going to the disc/drum at a later date?

                Comment


                • yes, that is my plan....
                  http://www.tbirdregistry.com/viewdat...ryNumber=33517

                  Comment


                  • David,
                    I'm not sure about the 70/30 split on the system either. I was told by the folks at Master Power Brakes that my combo valve was all I would need on my disc/drum system so I didn't go any further. You would enjoy the discs but just as well you will REALLY enjoy the discs after having the drums and converting. I had many reasons for converting but mainly to pull a wheelchair on a trailer.

                    Followed your link - great car to start from. Since you aren't concerned about originality you can probably just put bigger bolts on the firewall and stick a different master cyl on them, use what you have or however you decide. Power Brake Booster Exchange could probably rebuild that under dash booster as well if you want power brakes. That's kind of weird to have the under dash booster and no A/C but your dash definitely does NOT have the A/C vent blank cut out so guess that's how it came unless it was changed over the years.

                    Noticed the cloth inserts on the back seats - does your data plate say trim code 76? which would be factory cloth seat inserts (a little more rare than the vinyl or leather). Or maybe 76 trim code was just for the 60 model - anyway not as many cloth seat insert cars either 59 or 60. Mine is a 60 so more familiar with those.

                    Good luck and keep us posted on the progress.

                    Eric

                    Comment


                    • Originally posted by DKheld View Post
                      David,
                      ... That's kind of weird to have the under dash booster and no A/C but your dash definitely does NOT have the A/C vent blank cut out so guess that's how it came unless it was changed over the years...
                      That is the way mine was when I got it - KH booster and no AC. There was n o slot in the firewall for the AC unit. It's a little different now, AC and KH + MTM booster for disc/drum brakes.
                      sigpic "Old Betsy" - my '59 convertible J9YJ116209 Thunderbird Registry #33341

                      Comment


                      • Thx Eric, you're correct, I won't need to worry about the 70/30 part, the wheel cylinders make that up for you from what I've been told.
                        I don't know much about the setup I have but I did post the VIN info on the T-bird registry. I do like the cloth with the black vinyl seat. It didn't come with the front seats. I also like that it doesn't have AC or power windows - makes it lighter and easier to work on. So far I've pulled the gas tank and cleaned it, replaced the fuel pump, rebuilt the carb, replaced plugs and the wires. repacked the front bearings and greased all the tie-rods, check the shoes, rebuilt the windows and cranks and replaced the driver side glass. Put some $15 bucket seats in it from a local junk yard, cleaned out two squirrel nests and tons of pecan shells and sand. The lights, and horn etc all work.
                        My daughter wants to paint a square 59 on the roof in flat black. I told her she could do some flat black flames out the front wheel wells too. I want to put some cheater clicks on it eventually, A re-bar shift rod with brass knuckle shifter - tons of ideas to Rat it out. It was supposed to be a retirement project, but I could wait to start on it.
                        - Dave

                        Comment


                        • The final issue I had with my disc brake converison was getting a pedal that felt right. There was no problem with the braking ability but the pedal went uncomfortably close to the floor. The rest position of the brake pedal is controlled by the length of the push rod. Rather than fiddle around making a number of push rods of different lengths, I decided to make an adjustable one, see atached. It took a couple fitting adjustments to find a length that gives a good pedal feeling. One other thing I did was put a stainless steel plate and rubber gasket over the old MC hole in the firewall. The rubber gasket has slits to allow the push rod to move back and forth through it. Now I hope I have put this project to bed.
                          Attached Files
                          Last edited by Howard Prout; March 31st, 2011, 07:22 PM. Reason: corrections
                          sigpic "Old Betsy" - my '59 convertible J9YJ116209 Thunderbird Registry #33341

                          Comment


                          • SS Brakes makes an adjustable push rod and part of the "spongy" feeling is probably due to the firewall flexing.
                            sigpic
                            Jim

                            protourbird

                            Comment


                            • Because I retrofitted the AC system into my car, I was concerned that I may not have installed the AC plenum in exactly the same place as the factory. The space between my new booster and the AC plenum is only about 1/8". Ray is planning on changing his brake system this weekend so I asked him to check the distance between the flange on the AC plenum and the left fender edge on his car. The distance on my car is 14 1/4". He measured the distance on his car and it is 14 7/8" so clearance between the AC plenum and the new 8" booster is not an issue.
                              Attached Files
                              sigpic "Old Betsy" - my '59 convertible J9YJ116209 Thunderbird Registry #33341

                              Comment


                              • I redesigned the brackets so that they would be easier to fabricate. However I see in another thread that there are brackets for Jeeps that may be an easier solution yet.I haven't made a prototype or tested it in a vehicle, so while I am reasonably confident it will work, there are no guarantees. Both Ray and I have the previous version with the pinched brackets installed in our cars and they are working very well.
                                Attached Files
                                Last edited by Howard Prout; April 8th, 2012, 09:34 AM. Reason: Additions
                                sigpic "Old Betsy" - my '59 convertible J9YJ116209 Thunderbird Registry #33341

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