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  • Dual Master Cyls

    Fellow Car Nuts,

    Several years ago I modified the brakes on my '50 Champ Starlight Coupe (has a 145 h.p. Cathcart motor). I have the larger V-8 Brakes & Drums up front and a Turner Dual Cyl Kit installed. I am not happy with the performance of the Master Cyl that I installed. I believe that it is one of the #s that Jim listed in his kit directions. It is from a '76 non-power brake 'vette. It has a 1" piston as do all of those #s listed. Some are: '81-'84 Jeep, '78 Ranchero, etc .... Anyone with any experiences on this area? I'd like to try something more than a 1" piston Mst Cyl. Any & all help would be appreciated.

    Thinking Spring! (Hah!, just has 8" of white stuff again here in Suburban Detroit-Canton ....Yuch !!!) ..... [8D]

    StudeBakerHarv
    StudeBakerHarv
    * 1950 Champion Starlight Coupe (Cathcart Stg 4 Engine)
    * 1971 Avanti II (RQB-1659).

  • #2
    What is the problem with your brakes? Pedal effort, or front-rear balance?

    Gord Richmond, within Weasel range of the Alberta Badlands
    Gord Richmond, within Weasel range of the Alberta Badlands

    Comment


    • #3
      I got the Adjuster Valve with the Turner Kit, so Front-to-Rear balance is what I have dialed in and is good. It seems that pedal travel and feel are a bit soft and the brakes are not as effective in stopping the car as it should be. I've bled the brakes many times and adjusted the brakes too. A friend from the UK (excellent Tech guy) who drove the car suggested a Mstr Cyl with a larger Piston. Thanks. [8D]

      StudeBakerHarv
      StudeBakerHarv
      * 1950 Champion Starlight Coupe (Cathcart Stg 4 Engine)
      * 1971 Avanti II (RQB-1659).

      Comment


      • #4
        A larger piston will make your brakes firmer, but will actually *increase* pedal effort. A 1" master cylinder should duplicate the feel of an original V8 car, as that was the stock size.

        Not to ask dumb questions but *how* do you adjust your brakes? On a car without self adjusters, I prefer to adjust them until the star wheel simply won't turn any more and then back them off all the same number of clicks until the brakes drag about right. (about 8 or 9 clicks on my '55, but YMMV. I'd prefer to do it that way on a car with self adjusters, too, but it's a royal PITA to release the adjuster and turn the star wheel backwards. In that case I adjust, then pump the brakes a couple times to recenter the shoes, recheck adjustment, lather, rinse, repeat.) Also expect higher pedal effort and a softer feel until the shoes have completely worn in, unless you took the shoes and drums to a good old school shop and had the shoes arced to match the drums exactly. (does anyone still do that anymore?)

        nate

        --
        55 Commander Starlight
        http://members.cox.net/njnagel
        --
        55 Commander Starlight
        http://members.cox.net/njnagel

        Comment


        • #5
          I adjust just them like you mention. I turn the star wheel until there is drag and then back off until drag just disappears. I make sure that all is aligned and equal on both front brakes. Your shoe - drum match is a good thought. I think that they are matched pretty well as they have about 2500 miles on them. Got the drums, shoes & backing plates in a kit from Bill Cathcart back in '03. The rear brakes are not a concern as they work great. .... [8D]

          StudeBakerHarv
          StudeBakerHarv
          * 1950 Champion Starlight Coupe (Cathcart Stg 4 Engine)
          * 1971 Avanti II (RQB-1659).

          Comment


          • #6
            quote:Originally posted by Harv

            I adjust just them like you mention. I turn the star wheel until there is drag and then back off until drag just disappears. I make sure that all is aligned and equal on both front brakes.
            StudeBakerHarv
            Do as Nate suggests... Tighten them until you CANNOT rotate the wheel (backwards). Then loosen them 8-10 "clicks". I have had to go to 12 clicks before- but as stated YMMV.When adjusted in this way.. Your pedal should be very high and firm...
            IF you drive the car far enough to get the shoes "hot" and you start to get a front-end vibration- readjust another (2) clicks BOTH sides.

            Your way may have the shoes spread too far.

            Ray


            Specializing in Studebaker Restoration
            Ray

            www.raylinrestoration.com
            Specializing in Studebaker Restoration

            Comment


            • #7
              I'll give it a try.

              Thanks to all for your help on this. [8D]

              StudeBakerHarv
              StudeBakerHarv
              * 1950 Champion Starlight Coupe (Cathcart Stg 4 Engine)
              * 1971 Avanti II (RQB-1659).

              Comment


              • #8
                Sounds like you might have your shoes on backwards...The longer one goes in the back.

                Comment


                • #9
                  quote:Originally posted by N8N

                  A larger piston will make your brakes firmer, but will actually *increase* pedal effort. A 1" master cylinder should duplicate the feel of an original V8 car, as that was the stock size.


                  nate
                  After spemding the last month reading and re-reading Bob Johnstones's pages, I now have a "handle on some of this. A 1 inch bore will give you a 3 to 5 inch pedal, a 1.5 inch bore will give you a 2 to 4 inch pedal, but if your have any leg issues the innceased bore size will require much more effort on your part. Before you adjust your brakes, have you adjusted the mastr cylinder. Sounds weird, but in most Service Manuals Studebaker put the first paragraph last about adjusting brakes. Before you use the star wheel adjuster you must first adjust the pedal to where there is 3/8 th inch play at the pedal before the MC is engaged......then you adjust the star wheels.

                  The 1956 Servie Manual is a perfect example of poor editing. It goes thru two full pages of adjusting the brakes, then on the third page, it says..........."before making any adjustment to the brakes, you must adjust pedal travel tis is done as follows.

                  Like everyone else says, use a proportioning valve for the rears. BTW, did you install the check valves that come with the dual brake kit?

                  Comment


                  • #10
                    Harv; I sincerely hope that in your purchases and in our "help" we have not forgotten that most of these Dual Master Cyl. kits are sold for people using the excellent Jim Turner front Disc. conversion kit!

                    That said, I note that you are using the V-8 Drum Brake setup-all around! Now there is certainly nothing wrong with that on a light, only 145 H.P. "6", they should be more than enough brake.

                    BUT, what about the fact that front disc brake setup-ups require NO residual valves in the master, and setups with Drum Brakes DO require a residual valve!

                    So if you are using the Dual Master Cyl. for one of the more common Disc Brake situations, on a Drum Brake setup that REQUIRES TWO residual Valves, you are going to have problems!

                    Of course on Drum brakes, no proportioning valve should be needed.

                    StudeRich -Studebakers Northwest Ferndale, WA
                    StudeRich
                    Second Generation Stude Driver,
                    Proud '54 Starliner Owner

                    Comment


                    • #11
                      Rich & Other Helping Hands,

                      I believe that Rich may have hit on something. I remember installing the Turner Kit in '01. I recall not installing the RCVs at that time. Not sure why. The brakes never were really that great, just safer with the Dual Mstr Cyl. I just looked at the Turner Brake site and printed off the instruction page for the RCV installation. I'll put a #10 in the front line (Disc's get a #2 RCV) and a #10 in the rear line. I'll update you all on my progress. Snowy & Salty roads in the Great Lakes here so probably another 4 wks before I'll do a test drive on dry roads. Thanks so much for the help. [8D][8D][8D]

                      StudeBakerHarv
                      StudeBakerHarv
                      * 1950 Champion Starlight Coupe (Cathcart Stg 4 Engine)
                      * 1971 Avanti II (RQB-1659).

                      Comment


                      • #12
                        I believe it is 2 lbs to the front and ten to the rear. or a red one and a blue one. You need to dial in the proprtioning valve for balanced front rear. Check with Jim .....his e-mail is discbrake@insight.com.

                        He has helped me in the past few days

                        I just spent a week playing around with removing residual valves from the Jeep MC. Quite a bit of fun. Bob Johnsotne's pages has a complete set of instructions. If you find them and find the instruction to "find a 6 x32 self tapping screw I am now the KING on 6 x 32 self tapping screws. E-mial me and I will send you one....had to buy a box of 100 as no hardware store or Home Depot had them.

                        If you install the front residual valve in line as Jim provides, the one inside the MC will complicate your braking. Please if you do nothing else make sure you adjust the pedal before adjusting the shoes.

                        Trust me on this one, Ellen and I drove a 220 mile round trip with minor if no brakes because of the two residual valves in line

                        Comment


                        • #13
                          Watch it Bondo.........you may have the Malamouvis following you!![xx(]



                          quote:Originally posted by bondobilly

                          I believe it is 2 lbs to the front and ten to the rear. or a red one and a blue one. You need to dial in the proprtioning valve for balanced front rear. Check with Jim .....his e-mail is discbrake@insight.com.

                          He has helped me in the past few days

                          I just spent a week playing around with removing residual valves from the Jeep MC. Quite a bit of fun. Bob Johnsotne's pages has a complete set of instructions. If you find them and find the instruction to "find a 6 x32 self tapping screw I am now the KING on 6 x 32 self tapping screws. E-mial me and I will send you one....had to buy a box of 100 as no hardware store or Home Depot had them.

                          If you install the front residual valve in line as Jim provides, the one inside the MC will complicate your braking. Please if you do nothing else make sure you adjust the pedal before adjusting the shoes.

                          Trust me on this one, Ellen and I drove a 220 mile round trip with minor if no brakes because of the two residual valves in line

                          Comment


                          • #14
                            Looks like I have my work cut out for me here. What's the web address for Bob Johnstone's site? Also, how do I know if my Master Cyl already has check valves in it? I don't see any. I picked and have been using a Master Cyl that is not on the Turner Brake Instructions List. It fits great. It is a '76 Corvette / non-power brake Mstr Cyl (1" bore). Shows as #201371 or #10-1371 on the box and listed as such at Murray's Discount Auto Store (Detroit Area). [8D]

                            StudeBakerHarv
                            StudeBakerHarv
                            * 1950 Champion Starlight Coupe (Cathcart Stg 4 Engine)
                            * 1971 Avanti II (RQB-1659).

                            Comment


                            • #15
                              **Update time here.** Thanks to you guys for all of your help on this project. I did also have some excellent recent direction from Bob Johnstone too. The Brake Shoes were/are on correctly (longer ones in the back). I'll make the final mechanical tweaks to the brakes after I finish up on the MC. I followed Bob direction on his "36237 MC Prep" site for RCV removal. It was very easy installing the 6x32 screws to remove the inserts from my MC. It turns out that there we no RCVs under the inserts. I will definitely install those in-line RCVs that came with my Turner Kit. I'll be doing some work on the Coupe this weekend (after our WLEC chapter's event at the Henry Ford Museum in Dearborn tomorrow). [8D][8D][8D]

                              StudeBakerHarv
                              StudeBakerHarv
                              * 1950 Champion Starlight Coupe (Cathcart Stg 4 Engine)
                              * 1971 Avanti II (RQB-1659).

                              Comment

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