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  • Brakes: New discs installed, but right front skids

    Over the past weeks I have installed a Turner disc brake set up on a '64 Cruiser. The car came from the factory with standard drum brakes. I have retained the stock rear set up, but installed relined shoes and new cylinders. I've installed the '68 Dodge Monaco master cylinder that is commonly used for this type conversion, and a rebuilt power booster. I'm using Dot 5 fluid. All front suspension components have been replaced.

    When I make a panic type stop, the right front tire skids. When I try driving in the oncoming traffic lane on a lonely road to compensate for road-crown, its still the right front that skids. It does not lock up upon normal application of the brakes. Only on panic stops. So, if I was going 60 mph, and had to stop in a hurry, the car would tend to slide to a stop. That takes more distance, and its just not safe for other reasons as well.

    Anyone out there ever have anything like this happen or maybe know what's not right? I've already talked to Jim Turner, and he's at a loss for explanation ....

    Thanks,
    Larry

  • #2
    Since your front flexible brake hoses no doubt are new, (this is a common problem with old brake hoses which have collapsed inside), it could be a defective caliper....Drive the car to warm up the brakes, then stop and immediately jack the front up.....then see if the front wheels spin evenly when you spin them by hand....count the turns.

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    • #3
      I had a similar experience with my '83 Avanti where someone had added DOT3 to the existing factory DOT5 system. It really screws up ALL rubber components. I flushed the entire system, replaced ALL rubber and returned it to the factory DOT5. It did exactly what you described. I hope it turns out to be this simple for you Larry.
      Cheers, Bill

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      • #4
        you mean Dot 3 factory...

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        • #5
          No. Mine came from the Avanti factory with DOT5 and was duly noted on the master cylinder cover.

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          • #6
            Are you sure You have all the air out of the left caliper an air pocket in the left could reduce the apply pressure to that wheel . Try bleeding with pressure bleeder.
            I just yesterday put a new kit in the right rear wheel Cylinder on my Hawk of course I twisted off the bleeder screw tried to bleed By cracking the line. When I drove it left rear wheel would lock up with medium brake pressure. Right had been doing that internintly before due to cyl leak,
            Hawkowner

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            • #7
              We need more info on the Master Cylinder.
              If using the common AMC or Dodge Dual Master Cylinder depending on the Year, it is likely for Drum Brakes which would have the Residual Valve in BOTH circuits. You cannot use one on the Front (Rear Port) with Discs.

              Also I am surprised that you have not had Rear Brake Lockup, as those self-energizing Rears are not used with front Discs.
              StudeRich
              Second Generation Stude Driver,
              Proud '54 Starliner Owner
              SDC Member Since 1967

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              • #8
                The Dodge M/C being used is for disc fronts and drum rears. The check valve in the M/C is integrated into the outlet for the rears only. I installed a proportioning valve for the rears, and adjusted it way down, so I have some, but fairly minimal pressure/flow to the rears.

                Larry

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                • #9
                  I'd try a pressure bleeding of the system, and remove any residual valve in the master. The firewall mount master has enough height to usually eliminate the need for residual pressure to the rear drums.
                  One wheel lock up, off a shared brake line is either air (likely) or some obstruction in the brake line of the one not locking up, not a problem with the one that is.
                  If you can't find it, I would try borrowing or buying a pressure tester like this to see if it is line pressure or caliper problem: https://www.summitracing.com/parts/s...FYtXDQod7voFTw
                  Last edited by karterfred88; 01-29-2017, 02:24 PM.

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                  • #10
                    I agree, its either air, or damaged to rubber components due to mixing DOT 3 and 5. Was the DOT 5 conversion prior to any of the above mods? Also, when you installed the front calipers, were they set up new for DOT 5 or DOT 3 specifically, or a universal assembly lube used so it did not matter?

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                    • #11
                      I ran alcohol thru the system many times to flush out the old Dot 3. So many times it was probably overkill. I've maybe converted 12 to 15 Studes to Dot 5, and I've never had a contamination problem that I know of.

                      The Dot 5 was in the system when I rebuilt the drum brakes. I changed it over from Dot 3 when I bought the car, pretty much immediately. At that time it got all new cylinders. The
                      dot 3 never even touched the new cylinders.

                      That was a year or so ago. No problems were present with the drums. But, we plan on driving this car a lot, so that's why I wanted the discs.

                      Re-manufactured A-1 Cardone brand calipers are being used, as sold by Summit Racing. Same part number that Jim uses in his deluxe conversion kits. I do not open them up to inspect how nice the bore looks, or what kind of assembly lube was used. There is nothing on the box or within the package that warns against
                      dot 5 usage. I have 2 or 3 other cars in my inventory with Turner discs and Dot 5 and these same reman calipers. None has a problem with any wheel skidding.

                      Post #2 herein by SN-60 suggested a drive and spin test. I did so today, and both fronts had about the same spin count after the drive as before, so nothing learned there. Last night, for the third night in a row, I re-bled the front brake lines. Hose into the jar method, with hose submerged in fluid. No bubbles.

                      And the right front still skids on hard braking.

                      So I'm still looking for ideas.

                      Thanks again,
                      Larry

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                      • #12
                        Maybe there is a problem with the left front, if it is not braking as hard as the right front.

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                        • #13
                          The right side is "skidding" because it is locking up. Do the suggested diagnosis first. Plus, have someone apply the brakes while jacked up and compare the sides when under varying pressure, and do so as the components cool. Too many possible sources to tell for sure at this point exactly what's going on, imho. My one experience like this was a faulty caliper which was replaced correcting the problem. Best of luck and let us know what the culprit was when you locate it.

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                          • #14
                            Are the pads identical from side to side? Could they be from different manufacturers, or made from different materials, or different hardness?
                            RadioRoy, specializing in AM/FM conversions with auxiliary inputs for iPod/satellite/CD player. In the old car radio business since 1985.


                            10G-C1 - 51 Champion starlight coupe
                            4H-K5 - 53 Commander starliner hardtop
                            5H-D5 - 54 Commander Conestoga wagon

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                            • #15
                              Originally posted by SuperHawk View Post

                              Re-manufactured A-1 Cardone brand calipers are being used
                              Some years back I rebuilt Lockheed calipers using new custom chrome plated pistons, USA made grade 8 bolts, the best seals available, and caliper castings which had been glass bead blasted and electroless nickel plated inside and out. Assembled under near-clean room conditions, they were intended to be the best possible. I guaranteed them forever. Some have been on the road now for 25 years, including on my own car. Not one complaint yet.

                              It was difficult to find old salvage calipers which were not complete garbage, so I bought cheap rebuilts to use as my cores. I disassembled many of them. What I found inside them ranged from ugly to nasty to dangerous. None were really clean, all reused old, sometimes badly worn pistons and cheapo O-rings in place of proper seals.

                              Pull that caliper apart and see what is inside.
                              Last edited by jnormanh; 01-31-2017, 05:44 PM.

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