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  • #76
    This degree concern on the fittings is... annoying.
    Nobody seems to be willing to communicate on it. Whether brake manufacturers or fitting suppliers. I ended up cutting a measuring gage.
    Some are 37, some are 45.
    Attached Files

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    • #77
      Rookie question.
      When we bleed the brakes, do we need to have the engine running (to get the vacuum action from the engine) or is it just fine to use the pedal with engine at rest?

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      • #78
        No, you don't need the engine running.

        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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        • #79
          Locked home with limited access to the car, anybody could give me the dimension of the brake pedal from the pivot point to the middle of the pad (where the foot push) and from the pivot point to the hole on the pedal where the link attaches.

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          • #80
            HI ERIC....My 59 has been modified for a Disc Brake kit as well...This car had the Kelsey hayes power brake assist package..which means a very complicated brake pedal assmbly. ..The measurement from pivot to pedal pad center, is 14 inches . and pivot to master cyl rod is 2 inches, {very hard to measure as car is all together.}.. for a ratio of 7 to 1. this ratio is a little high { I think it shd be around 5 or 6 to one for power brks}...But soooo hard to modify stock pedal master cyl rod attachment point on this car. New Master cyl bore is 1 inch... This set up works very well. the pedal feels stock and this kit has been an unreal addition to this car....Hope this helps you CHEERS TERRY

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            • #81
              Hi Terry
              I finally just made it out to measure my stock pedal. It is 33/5cm for a 6.6 ratio. MBM Brakes asks for 1:6 on power brakes.
              I can confirm it's tricky to measure the pedal in place !
              MBM made a mistake and sent a 1.125" M/C. I told them 2 times and they overlooked it and sent it so I thought they knew what they were doing and it should works.
              This being said they will replace it but they also think that a 6.6 ratio should overcome the size difference so they are looking at other possible problems.
              The car just do not brake, it takes it several meters/yards to stop from 20 M/h with 2 feet on pedal !
              All normal troubleshooting checked (bleeding, vacuum, ...)

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              • #82
                Hi Eric ....I see you have had some good suggestions on this problem ...I would put a press guage on the front Caliper AND rear brake cyls. {adaptors screw into bleeder screw ports } You must have around 1000 psi at the caliper to lock up Disc brakes..{Full pedal pressure applied} ..A pressure guage kit is about 60 to 80 bucks from a parts house....with the amount of trouble you have had , this would be a good investment.{.then you can loan it to a friend, and never see it again.}.......The rear brks lock at 600 psi....The Combination valve controls the press difference front to back...if you are using a GM style combo valve it must be bled with the PIN under the rubber cover plug HELD IN. A two person job,,, Or you must use a tool that screws into the electrical warning light port on the top....Easier to see a better explanation if you go online and read about Combination Valves. how to bleed...I dont know the diameter of the booster you are using, it must be at least 8 to 9 inches, double diaphram booster , to work properly with around 16 to 18 inches of eng vaccuum.. and of course you must be taking the vacuum from a separate port in the intake manifold, or full vac port on the carb..Hope this helps you.....A custom brake setup can be apain, as you are finding out...I think a 1.125 master cyl would be ok . with your pedal ratio, if the Booster is sized ok with good vacuum....BUT...the brake pressures will tell you for sure.The brake pressure check NEVER LIES ...CHEERS TERRY

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                • #83
                  Terry

                  I will check with this combination valve bleeding. Jopizz said here that this valve do not need any special attention to be bled : When you bleed the brakes after everything is back together that will bleed the proportioning valve.
                  Booster is 8", MBM brakes also said that the pedal ratio at 6+ should overcome the size difference (1" Vs 1.125")
                  Vaccuum has been plugged using the same hose the original set up (that did worked) used.
                  Looking forward to read further from MBM and will check how the pedal goes with master cylinder removed from the booster. So I can make sure nothing prevent the pedal from moving !?

                  Thank you for your help so far Terry.
                  (Forums are quiet these days, everybody is stuck at home worldwide, I was expecting a surge in messages but all forums are quiet... Probably some garages/houses/gardens are being attended at (my case !))

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                  • #84
                    Hi Eric....you can easily check your pedal travel in the master cyl as I mentioned in an earlier post....Remove m/cyl cover.....have someone move the brake pedal slowly through it's full travel , up and down...You can look into the reservoir, down thru the fluid and see the compensation ports. SMALL HOLES IN THE BOTTOM OF BOTH RESERVOIRS.........you can see the piston move back and forth.....as the piston covers/uncovers the ports you SHOULD see fluid flow into the reservoir, from this port....you shd see it in both the front and rear reservoir. ....if you see this....it indicates the pedal travel and proper relationship to the Master cyl is good. you really should look up Compensation ports, Master Cylinder...This is VERY GOOD INFO that explains a lot about master cyl operation. also Jopizz is correct on some Combo valves...Make sure you look up YOUR SPECIFIC VALVE, for the proper procedure.. Stay healthy, we are good here { so far} in the interior of BC Canada..CHEERS TERRY

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