67 Corvette Caliper Date Decode - NCRS Discussion Boards

67 Corvette Caliper Date Decode

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  • David S.
    Very Frequent User
    • August 9, 2009
    • 595

    67 Corvette Caliper Date Decode

    How do you decode the date on a 545 caliper? It says 237.

    Thanks,
    Dave
  • Joe L.
    Beyond Control Poster
    • February 1, 1988
    • 43193

    #2
    Re: 67 Corvette Caliper Date Decode

    Originally posted by David Schutzbank (50698)
    How do you decode the date on a 545 caliper? It says 237.

    Thanks,
    Dave

    Dave------


    Assuming that series of numbers actually represent a julian date code (which I do not believe anyone has confirmed), they would represent the 237th day of whatever year. IF this series does represent a julian date code, there is no reference to year. Of course, the "545" series calipers were only manufactured from 1967 to about 1973, so it pretty much has to be one of those years.
    In Appreciation of John Hinckley

    Comment

    • Kenneth B.
      Extremely Frequent Poster
      • August 31, 1984
      • 2084

      #3
      Re: 67 Corvette Caliper Date Decode

      Originally posted by David Schutzbank (50698)
      How do you decode the date on a 545 caliper? It says 237.

      Thanks,
      Dave
      I beleave it would be FEB 3 1967. most castongs from that that time used the month/day/year. I built foundry tooling for 47 years.
      KEN
      65 350 TI CONV 67 J56 435 CONV,67,390/AIR CONV,70 454/air CONV,
      What A MAN WON'T SPEND TO GIVE HIS ASS A RIDE

      Comment

      • Joe L.
        Beyond Control Poster
        • February 1, 1988
        • 43193

        #4
        Re: 67 Corvette Caliper Date Decode

        Originally posted by Kenneth Barry (7808)
        I beleave it would be FEB 3 1967. most castongs from that that time used the month/day/year. I built foundry tooling for 47 years.
        KEN

        Ken------



        Yes, most castings did use the format you describe. However, many of these brake castings were cast at the old GM foundry in Danville, IL. Danville often used julian date coding, particularly on pieces cast for Delco-Moraine. For some reason, Delco-Moraine "liked" julian date coding and generally used it even on stamped date codes which they applied, although those almost always contained a reference to year.

        In addition, for the date coding format you described to have been used would have required that, in some cases, there would have needed to be 4 or 5 digits (e.g. October 5, 1967 or October 23, 1967). I have never seen more than 3 digits used for one of these presumed casting date codes.

        Also, on the known original "545" caliper halves on my 1969 only one caliper half of the eight on the car ends with an "8" and none ends with a "9". In my opinion, this virtually rules out that the final digit of the 3 digit series represents a reference to year.
        In Appreciation of John Hinckley

        Comment

        • Wayne M.
          Expired
          • March 1, 1980
          • 6414

          #5
          Re: 67 Corvette Caliper Date Decode

          Originally posted by Joe Lucia (12484)
          Dave------


          Assuming that series of numbers actually represent a julian date code (which I do not believe anyone has confirmed), they would represent the 237th day of whatever year. IF this series does represent a julian date code, there is no reference to year. Of course, the "545" series calipers were only manufactured from 1967 to about 1973, so it pretty much has to be one of those years.
          I have a strong hunch that Julian was the word for the 1st design '65-67E calipers; [546... series]. Here's what I believe are the originals off my Aug 2nd 1965 car.

          front inboards 5465954 "155" and "130" (see pic below).
          front outboards 5465952 "153" and "147"
          rear outboards 5465905 "96" (both)
          rear inboards 5465902 "119" and "99".

          So all castings grouped from 1st week of April to 1st week of June.

          Comment

          • Joe L.
            Beyond Control Poster
            • February 1, 1988
            • 43193

            #6
            Re: 67 Corvette Caliper Date Decode

            Originally posted by Wayne Midkiff (3437)
            I have a strong hunch that Julian was the word for the 1st design '65-67E calipers; [546... series]. Here's what I believe are the originals off my Aug 2nd 1965 car.

            front inboards 5465954 "155" and "130" (see pic below).
            front outboards 5465952 "153" and "147"
            rear outboards 5465905 "96" (both)
            rear inboards 5465902 "119" and "99".

            So all castings grouped from 1st week of April to 1st week of June.


            Wayne-----


            It's interesting that these do not use place bolts for caliper half retention. All original 1st design calipers that I've seen use the place bolts.

            Also, something else I should have noted, the "547" (i.e "third design") calipers used from about 1973 through 1982 do often use a month-day-year dating format, although some use the same julian system as earlier. However, I don't think that these were cast in a GM foundry. I think these were "outsourced". At the very least, if they were cast at a GM foundry, it was not Danville, IL. The "547" calipers are not even the same material. They are gray iron. The "546" and "545" are ductile iron.
            In Appreciation of John Hinckley

            Comment

            • Wayne M.
              Expired
              • March 1, 1980
              • 6414

              #7
              Re: 67 Corvette Caliper Date Decode

              Originally posted by Joe Lucia (12484)
              ....It's interesting that these do not use place bolts for caliper half retention. All original 1st design calipers that I've seen use the place bolts......
              Joe - that shot zoomed in too close; those TR bolts you see are the caliper mount bolts. You can barely see part of the place bolt on the right.

              Here's another shot of same caliper. Notice the bleeder valve is broken off.

              Comment

              • Joe L.
                Beyond Control Poster
                • February 1, 1988
                • 43193

                #8
                Re: 67 Corvette Caliper Date Decode

                Originally posted by Wayne Midkiff (3437)
                Joe - that shot zoomed in too close; those TR bolts you see are the caliper mount bolts. You can barely see part of the place bolt on the right.

                Here's another shot of same caliper. Notice the bleeder valve is broken off.


                Wayne-----


                I don't know how I made that mistake. Even in the original photo it should be obvious that the bolts shown are the caliper mounting bolts.
                In Appreciation of John Hinckley

                Comment

                • Ronald L.
                  Extremely Frequent Poster
                  • October 18, 2009
                  • 3248

                  #9
                  Re: 67 Corvette Caliper Date Decode

                  Wayne, Joe,
                  What do you guys make of this first design caliper???

                  Comment

                  • Patrick H.
                    Beyond Control Poster
                    • December 1, 1989
                    • 11608

                    #10
                    Re: 67 Corvette Caliper Date Decode

                    Originally posted by Wayne Midkiff (3437)
                    I have a strong hunch that Julian was the word for the 1st design '65-67E calipers; [546... series]. Here's what I believe are the originals off my Aug 2nd 1965 car.

                    front inboards 5465954 "155" and "130" (see pic below).
                    front outboards 5465952 "153" and "147"
                    rear outboards 5465905 "96" (both)
                    rear inboards 5465902 "119" and "99".

                    So all castings grouped from 1st week of April to 1st week of June.

                    Wayne,

                    It is the opinion of some of us that the numbers you're showing in the casting (eg. 130 in the photo above) are not the date codes. The date codes are stamped in tiny numbers on the top of the caliper, same size and font as the tiny ones for the date code on the master cylinder. On a few cars with original calipers the stamped date codes do seem to line up.

                    Below is a "136" stamped in a caliper. Sorry for the silver paint which fills in the numbers a bit. My attempt at keeping a "machined look" while preventing rust.

                    Patrick

                    Vice-Chairman (West), Michigan Chapter NCRS
                    71 "deer modified" coupe
                    72 5-Star Bowtie / Duntov coupe. https://www.flickr.com/photos/124695...57649252735124
                    2008 coupe
                    Available stickers: Engine suffix code, exhaust tips & mufflers, shocks, AIR diverter valve broadcast code.

                    Comment

                    • Joe L.
                      Beyond Control Poster
                      • February 1, 1988
                      • 43193

                      #11
                      Re: 67 Corvette Caliper Date Decode

                      Originally posted by Patrick Hulst (16386)
                      Wayne,

                      It is the opinion of some of us that the numbers you're showing in the casting (eg. 130 in the photo above) are not the date codes. The date codes are stamped in tiny numbers on the top of the caliper, same size and font as the tiny ones for the date code on the master cylinder. On a few cars with original calipers the stamped date codes do seem to line up.

                      Below is a "136" stamped in a caliper. Sorry for the silver paint which fills in the numbers a bit. My attempt at keeping a "machined look" while preventing rust.

                      Patrick


                      Patrick------


                      I agree that there's uncertainty as to whether the raised 3 digit series on the caliper castings represents a date. In the case of my original owner 1969, these series of characters cast on each caliper half are widely disparate which, if they were dates, would mean that the caliper halves were cast over a very long time period and much longer than I would expect for cast parts. Certainly, if it is a date code, the code contains no reference to year.

                      However, it is very possible the raised 3 digit code and the stamped 3 digit code are, in fact BOTH date codes. The raised code would then be the CASTING date and the STAMPED code would be the date of machining and/or caliper assembly. If so, of course, the stamped code would have to be the same or successive to the cast code.
                      In Appreciation of John Hinckley

                      Comment

                      • Patrick H.
                        Beyond Control Poster
                        • December 1, 1989
                        • 11608

                        #12
                        Re: 67 Corvette Caliper Date Decode

                        Originally posted by Joe Lucia (12484)
                        Patrick------


                        I agree that there's uncertainty as to whether the raised 3 digit series on the caliper castings represents a date. In the case of my original owner 1969, these series of characters cast on each caliper half are widely disparate which, if they were dates, would mean that the caliper halves were cast over a very long time period and much longer than I would expect for cast parts. Certainly, if it is a date code, the code contains no reference to year.

                        However, it is very possible the raised 3 digit code and the stamped 3 digit code are, in fact BOTH date codes. The raised code would then be the CASTING date and the STAMPED code would be the date of machining and/or caliper assembly. If so, of course, the stamped code would have to be the same or successive to the cast code.
                        Joe,

                        Definitely possible.
                        However, I suspect so few cars retain their original calipers that to study this and make any sort of worthwhile analysis is almost impossible.

                        Patrick
                        Vice-Chairman (West), Michigan Chapter NCRS
                        71 "deer modified" coupe
                        72 5-Star Bowtie / Duntov coupe. https://www.flickr.com/photos/124695...57649252735124
                        2008 coupe
                        Available stickers: Engine suffix code, exhaust tips & mufflers, shocks, AIR diverter valve broadcast code.

                        Comment

                        • Wayne M.
                          Expired
                          • March 1, 1980
                          • 6414

                          #13
                          Re: 67 Corvette Caliper Date Decode

                          Originally posted by Patrick Hulst (16386)
                          ....I suspect so few cars retain their original calipers that to study this and make any sort of worthwhile analysis is almost impossible......

                          Certainly true, especially 45 or so years after production. However, in the case of my late late '65 calipers, I believe they are original, due to remnants of the orange paint daubs on the inboard halves of each rear caliper. There is a Tech Service Bulletin out there (tried to locate, as it has been discussed on the DB) about complaints of rear brake squeaking; corrected by triming material from the shoe edges. Those late '65 and early '66 cars so affected (prior to shoe design change) were to be identified with orange paint, per the TSB.

                          Dang, I wish I could find this thread.

                          P.S. 3rd last line of primary paragraph -- I typed the version of trim with 2 'm's and the censor blanks out the letters following the 't' with asterisks, even though the spell check now flags it red with one 'm'. Have I offended some unknown language or religion ?
                          Attached Files

                          Comment

                          • Terry M.
                            Beyond Control Poster
                            • September 30, 1980
                            • 15573

                            #14
                            Re: 67 Corvette Caliper Date Decode

                            Originally posted by Wayne Midkiff (3437)
                            P.S. 3rd last line of primary paragraph -- I typed the version of trim with 2 'm's and the censor blanks out the letters following the 't' with asterisks, even though the spell check now flags it red with one 'm'. Have I offended some unknown language or religion ?
                            It is the part of the word that was replaced with asterisks the censor bot does not like. I could try to explain it to you, but i doubt much of my explanation would get past the censor, and besides this IS a family board.
                            Terry

                            Comment

                            • Ronald L.
                              Extremely Frequent Poster
                              • October 18, 2009
                              • 3248

                              #15
                              Re: 67 Corvette Caliper Date Decode

                              Wayne,
                              Are these the head marks you have on your place bolts?

                              Anyone know what the numbers and letters mean???
                              Attached Files

                              Comment

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