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Motor Bulkhead/Cylinder Union Leak

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  • Motor Bulkhead/Cylinder Union Leak

    I have a tiny leak where the Motor Bulkead Seals to the Cylinder.
    I replaced the O Ring, still a leak. My understanding is that the bulkheads are produced and matched to a cylinder.
    What options do I have? This is the USS Blueback, with the 11/2” Subdriver from Bob.

  • #2
    I hear wrapping teflon tape around the endcap before putting in back into the cylinder helps.
    Make it simple, make strong, make it work!


    • #3
      I assume you mean 2 1/2" cylinder? And is it the SD or MSD type? Is the leaking O-ring evidencing a solid black 'bead' when made up to the cylinder. If not it's loose?

      You might remove the O-ring, examine the groove and look for dirt or flaws in the channel. Insure the O-ring is clean and well greased.

      Keep me informed. We'll fix this!

      "... well, that takes care of Jorgenson's theory!"


      • #4
        Yes, 21/2”. The leak does not exhibit a black bead, I will do as suggested and inspect the O ring and channel. It seems too easy to slide the bulkhead in, it is not as tight as it was originally?
        The teflon tape is an idea I have considered.


        • #5


          • #6
            The O Ring and channel are as should be... the fit seems loose, not as tight as the battery bulkhead. When I do blow test with the hose the bulkhead wants to push out of the cylinder. Maybe the cylinder expanded from my shop heat?
            Dave, any thoughts on yrying teflon tape? I hate the idea of it not being as should be without tape etc.


            • #7
              I would not worry about using teflon tape. It helps a lot.
              Click image for larger version

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              That repair was done 7 or 8 years go and still works great.

              If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.


              • #8
                Post a bigger photo. OK, that's an SD type. Are there any hair-line cracks of the cylinder over the O-ring?

                "... well, that takes care of Jorgenson's theory!"


                • #9
                  Thanks Tom, so you put the teflon under the O Ring?
                  Dave, sorry yes, SD type, no hairlines visible, will post larger photo, momentarily


                  • #10


                    • #11
                      Guys, just occured to me I should call it the motor housing cap, not bulkhead?


                      • #12
                        Originally posted by biggsgolf View Post
                        Guys, just occured to me I should call it the motor housing cap, not bulkhead?
                        Motor bulkhead, damnit!... motor bulkhead!

                        "... well, that takes care of Jorgenson's theory!"


                        • #13
                          Hahaha, one of my most favorite quotes!


                          • #14
                            Here is leak video uploaded to youtube


                            • #15
                              Dave, sorry, yes the O Ring seems to have a thin black bead all the way around, I was confused