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Prop Valve 4 Whl Disc Brake Avanti/interim update

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  • Prop Valve 4 Whl Disc Brake Avanti/interim update

    I bought an extra booster on ebay awhile ago and it had a Strange ( probably the same as a Willwood) Disc/Disc Master Cylinder attached with a nice homemade adapter. It was a good purchase for two reasons. The rebuilt booster I purchased from one of our vendors whistles and stops working intermittently, it's maybe 18 moths old but with very few miles and the 'free' master cylinder may solve some issues with my brakes.



    So I took the part number from it and started researching which led me to Master Power Brakes website. According to them a Disc/Drum master cylinder will not work properly with a 4 wheel disc application.

    They also made a point of using the handbrake consistently on the Eldorado calipers. Seems they adjust mechanically via the handbrake and not using it will result in reduced braking power.

    So, I'll be installing The Strange Disc/Disc master initially with no prop valve. Out of curiosity I'm thinking of rigging the disc/drum master so I can take a pressure reading on the back reservoir on the car first. I've never felt the rear brakes were working properly with the dual conversion master. It may yield some good info for future conversions.

    BTW, the new brakes are going on my freshly rebuilt Dana 44. I forgot to take a picture of the final mesh pattern but I was happy with it. I know running up in the air tells very little but I was happy to hear...nothing. I put my stethescope to the axles and just heard some nice whirring sounds. Hope it's like that on the road.


    Initial post...

    Can anyone tell me from experience with their 4 wheel disc brake installation whether a proportioning valve is necessary?

    Part two: Anyone have an adjustable prop valve installed with a pressure gage? Looking for ideas on placement if I install the valve.

    64 R2 Avanti Dual master Turner disc front and now rear.

    ErnieR


    On its way to a 15.097 Island Dragway Great Meadows NJ Spring 2006.

  • #2

    I have Turner's kit on the front and Steel-Tech stuff on the rear with no prop valve. I can stand on the pedal and come to a very quick stop without locking any of the wheels..


    Bob Johnstone
    www.studebaker-info.org

    64 GT Hawk
    55 President State Sedan
    70 Avanti (R3)
    64 GT Hawk (K7)
    1970 Avanti (R3)

    Comment


    • #3
      Thanks Bob, I'll try it without the valve first. Hopefully, one less thing to do.

      ErnieR


      On its way to a 15.097 Island Dragway Great Meadows NJ Spring 2006.

      Comment


      • #4
        Question.
        What is a gauge going to tell you?
        Most people use a pressure gauge to 'set' the brakes on the starting line consistently.
        Summit sells a nice one that incorporates the distribution block and even has a brake light switch...
        http://www.summitracing.com/parts/SUM-G3910/

        Makes for a cleaner install.
        Summit sells a bunch of brake pressure gauges...
        Here's a search.
        http://www.summitracing.com/search/?...%20gauge&dds=1

        That R3 (Clone) Avanti I worked on had an adjustable proportioning valve installed. The plumbing was less than appealing.


        HTIH (Hope The Info Helps)

        Jeff


        Get your facts first, and then you can distort them as much as you please. Mark Twain



        Note: SDC# 070190 (and earlier...)

        Comment


        • #5
          The gage will tell me if i have enough pressure to the back wheels. 800-1000 is recommended for disc brakes. Living in heavily populated NJ my opportunities for brake testing are limited. It's possible that things may feel right because the rears don't lock but it may be because they are barely working.

          I have a Summit prop valve and gage without the brake switch, I converted to mechanical. The prop valve should be installed after the junction block in the single line going to the rear brakes according to instructions with the valve. Which means somewhere under the car or bringing lines up into the passenger or engine compartment if I wanted to adjust while testing.

          I always questioned whether my drum brakes were getting enough pressure with the dual master conversion. They never seemed to do much. With the Turner brakes up front the car stops deceptively well, meaning it feels like it should but I want to be sure the backs are doing something.

          I may plumb the gage inline first, I have a spot under the hood where the hydraulic switch was before I converted to mechanical. If the pressure looks good I'll forgo the prop valve.

          We'll see.


          On its way to a 15.097 Island Dragway Great Meadows NJ Spring 2006.

          Comment


          • #6
            The reason a disc/drum master won't work on disc/disc is because the master cylinder bore sizes are different 'within' a disc/drum master.
            A disc/disc master has the same bore size for both the front and the rear.
            Pay attention to the bore size on the master, as it will affect your foot pressure required.
            Eldo/Toronado/Riviera rear calipers work well, but watch how they mount on your caliper brackets.
            A lot of them get mounted to get a good parking brake cable alignment, but thet gets you a real bad bleeder screw position.
            That usually means you have you have to remove and clamp the caliper piston to bleed the brakes (initially)
            Their comment about parking brake adjustment affecting normal brake application is true.
            That style caliper had a six sided hex bolt type caliper piston adjusting screw on it.
            You load up your caliper/rotor setup and bleed your brakes.
            Then you crank the parking brake lever as far as it will go (until the pads hit the rotor)
            (I did this by hand before installing the parking brake cable(s).
            If you are far enough along in rotation before the pads contact the rotor, you remove the parking brake lever and put it on the next hex (60 degree's).
            If you don't do this, then in normal use the caliper piston retracts quite a bit. This means that you lose pedal stroke just getting the pad pushed to the piston.
            It really isn't a big deal, and it shouldn't chase you off that style caliper.
            Once you adjust it the first time, you only adjust it for pad wear...
            And it takes a LOT of pad wear to get the parking brake lever to move 60 degree's.
            I am running this basic setup on the yellow truck, and it works great.
            (Except I am running a hydroboost power brake setup)
            Hang in there... You'll get it sorted out.
            BTW... I am not running an adjustable proportioning valve, but am running a stock GM proportioning/distribution block (off an Eldo/Riviera/Toronado.
            HTIH
            Jeff[8D]

            PS: Strange Engineering makes great stuff. I've bought a lot of Bob Stange's stuff through the years. Good drag race supplier..


            HTIH (Hope The Info Helps)

            Jeff


            Get your facts first, and then you can distort them as much as you please. Mark Twain



            Note: SDC# 070190 (and earlier...)

            Comment


            • #7
              Great info on the caliper adjustment, thanks. This is Jim Turner's kit but I didn't see anything about the initial adjustments in the instructions. I think I'll be OK with the bleeder it sits up high enough that I think it will bleed ok.

              Just so I understand, once I'm bled I set the parking brake. If I have good squeeze before the lever moves its full travel I'm good but if it doesn't I remove the lever and position it such that I get enough travel to set the brake without bottoming the lever.

              So to alter my original question...would you, with your experience, install a non-adjustable prop valve?

              I think I'm good with the bore size it's 1.125.

              Thanks for the help Jeff.


              On its way to a 15.097 Island Dragway Great Meadows NJ Spring 2006.

              Comment


              • #8
                Hey Bige-

                You may have bought that setup from me.

                I sold one with a Wilwood/Strange master attached some while back on Ebay -it was kind of an olive drab green color.

                Anyhow, Master Power has a lot of good info on their site and the Wilwood guys were pretty helpful with me on the phone during the design of my new dual disc system which is comprised of independent masters for front and rear and no booster.

                I'll definitely be running a valve so I can dial the brakes in exactly the way I want them -I just hope I did all my math right [:0]

                Just got the car back from the muffler shop, and it's ashame that the job they did will rarely be seen. That's one of the problems with lowered cars -people don't wanna crawl around on the ground to see the party underneath!!



                http://community.webshots.com/user/s...host=community

                Comment


                • #9
                  Great description of how the caliper should adjust.
                  Basically, you rotate the pbrake lever as far as you can until it stops.
                  If you can get it to the next hex...go for it.
                  (like swinging a box end wrench in a confined space).
                  It won't retract, because you don't have the spring and cable hooked up.
                  After you are done, pop the spring back on and feed the cable through and hook the ball end up.

                  As far as the master cylinder goes?
                  Bore diameter on the master cylinder depends on the piston diameter and piston travel of the calipers.
                  The smaller the piston in the master cylinder, the higher the psi load on the caliper 'per pound of pedal effort'.
                  You can get a real high psi load, but you might not have the volume needed to move the calipers far enough.
                  A larger bore master cylinder will get more fluid into the caliper, but the pedal effort goes up with each bore increase at the master.
                  I tried a 1&5/16" bore master once, but the pedal effort went way up.
                  Settled on a manual disc/disc Corvette master cylinder at a 1" bore and it worked well without too much pedal stroke.
                  Sounds like you are right in the ballpark with your size..

                  As far as the valve goes?
                  Here's what I am running...

                  This is basically the same valve from MP Brakes:
                  http://www.mpbrakes.com/products/pro...product_id=613

                  It is a non adjustable valve.
                  An adjustable valve in the back line can still be added for adjustability...With or without this valve.
                  If you do install an adjustable after this valve the adjustable part won't start until after the non adjustable valve has done it's part.
                  I got my valve when I got the calipers for their brackets.
                  I figured I could add an adjustable valve later, after testing to see if I needed it.
                  My method of testing was crude and somewhat violent.
                  Go fast...Stop fast...Repeat.
                  (Testing continues to this day)
                  Jeff[8D]



                  quote:Originally posted by bige

                  <snip>
                  Just so I understand, once I'm bled I set the parking brake. If I have good squeeze before the lever moves its full travel I'm good but if it doesn't I remove the lever and position it such that I get enough travel to set the brake without bottoming the lever.

                  So to alter my original question...would you, with your experience, install a non-adjustable prop valve?
                  I think I'm good with the bore size it's 1.125.
                  Thanks for the help Jeff.
                  HTIH (Hope The Info Helps)

                  Jeff


                  Get your facts first, and then you can distort them as much as you please. Mark Twain



                  Note: SDC# 070190 (and earlier...)

                  Comment


                  • #10
                    I'm sure it was yours...I haven't seen that combo before or since.

                    Thanks BTW.

                    quote:Originally posted by wcarroll@outrageous.net

                    Hey Bige-

                    You may have bought that setup from me.

                    I sold one with a Wilwood/Strange master attached some while back on Ebay -it was kind of an olive drab green color.

                    Anyhow, Master Power has a lot of good info on their site and the Wilwood guys were pretty helpful with me on the phone during the design of my new dual disc system which is comprised of independent masters for front and rear and no booster.

                    I'll definitely be running a valve so I can dial the brakes in exactly the way I want them -I just hope I did all my math right [:0]

                    Just got the car back from the muffler shop, and it's ashame that the job they did will rarely be seen. That's one of the problems with lowered cars -people don't wanna crawl around on the ground to see the party underneath!!



                    http://community.webshots.com/user/s...host=community

                    On its way to a 15.097 Island Dragway Great Meadows NJ Spring 2006.

                    Comment


                    • #11

                      I use a Master Power Brake VL3350 combo valve on my Hawk

                      <http://www.studebaker-info.org/64v24...0407ea.jpg>

                      with Turner Disks


                      Bob Johnstone
                      www.studebaker-info.org

                      64 GT Hawk
                      55 President State Sedan
                      70 Avanti (R3)
                      64 GT Hawk (K7)
                      1970 Avanti (R3)

                      Comment


                      • #12
                        Just an FYI...The VL3350 is for disc/drum, and BigE is running disc/disc, so he'd use a VL3359A..
                        Nice plumbing work.
                        Nice pic labels.
                        Just plain nice!
                        Jeff[8D]


                        quote:Originally posted by 55Prez


                        I use a Master Power Brake VL3350 combo valve on my Hawk
                        with Turner Disks
                        <http://www.studebaker-info.org/64v24...0407ea.jpg>
                        <snip>
                        HTIH (Hope The Info Helps)

                        Jeff


                        Get your facts first, and then you can distort them as much as you please. Mark Twain



                        Note: SDC# 070190 (and earlier...)

                        Comment


                        • #13
                          I ordered the 3359.

                          Thanks for all the help.

                          While I have the attention of some obviously smart guys...

                          On many factory brake systems the lines from the master have multiple loops even though a straight line would have worked...

                          WHY?


                          On its way to a 15.097 Island Dragway Great Meadows NJ Spring 2006.

                          Comment


                          • #14
                            My understanding is the loops allow a greater area for flex and vibration to work itself out to lessen cracking of the hard lines.

                            Jim

                            ____1966 Avanti II RQA 0088_______________1963 Avanti R2 63R3152____________Rabid Snail Racing
                            Jim
                            Often in error, never in doubt
                            http://rabidsnailracing.blogspot.com/

                            ____1966 Avanti II RQA 0088_______________1963 Avanti R2 63R3152____________http://rabidsnailracing.blogspot.com/

                            Comment


                            • #15
                              Makes Sense...

                              Thanks Jim

                              quote:Originally posted by jlmccuan

                              My understanding is the loops allow a greater area for flex and vibration to work itself out to lessen cracking of the hard lines.

                              Jim

                              ____1966 Avanti II RQA 0088_______________1963 Avanti R2 63R3152____________Rabid Snail Racing

                              Comment

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