[Reference] Fuel tank lockring - repop comparison

General Mopar Tech Discussions

  1. cudak888

    cudak888 Well-Known Member

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    I'm posting this as a future reference for members and B-body owners Googling for this topic. It is also a good read for owners unaware of this issue (heck, your tank may be leaking and you don't know it). Photos are at the bottom of the writeup:

    Most repop B-body senders that are commonly available (Dorman or Spectra) are bottom-of-the-barrel Chinese repops. They are what they are. Unfortunately, these senders also have new lockrings packaged with them. Many of you know not to use these lockrings that are included with repop senders. They are much thinner than the originals and will not put enough pressure on the sender gasket to seal properly. You will have a leak at the bottom of the sender which will become a bit alarming after a while; fuel will pool at the fused lip and forward center edge of the tank.

    Most anyone with a bit of auto repair experience, given both an original and a repop in their hands during a project, will take one look at the repop and throw it away in favor of the original. However, some of us also end up acquiring half-finished project cars, and these half-finished cars often come with bad repairs - such as a new sender installed with one of these lockrings.

    This was the case with my car, which was slowly dripping fuel out the sender gasket. Being my first B-body, I wanted to get visual confirmation that I had the "wrong" lockring, because - apparently - the aftermarket also sells a correctly reproduced lockring with the factory thickness and build quality. How should I tell the two apart if I've never seen what the crappy one looks like vs. a good quality reproduction?

    Well, you don't. But thanks to a tip in a thread by forum member themechanic, I bought a new repop lockring said to be of the proper thickness of the original. This alternate repop came from Bill Rolik Enterprises, and even he wasn't aware that there was a bad repop out there - hence, it's not even noted as being the "correct" lockring on his website.

    And so, today, I finally dropped my way-too-full (isn't it always when you have a job like this?) fuel tank to compare and swap lockrings. And when doing so, I had the chance to photograph the stark difference between these two lockrings.

    So, without further ado, here are two closeup comparisons between the way-too-thin "packaged with sender" replacement lockring, and the properly reproduced part I bought from Bill Rolik Enterprises:

    Crappy Chinese Spectra/Dorman lockring at left, Bill's repop at right. The quality difference should be obvious:

    [​IMG]

    Crap on top, good one on the bottom:

    [​IMG]

    A few additional photos. Note that you never loop those two vents on the gas tank - I did this only to prevent getting a face full of fuel when dropping the tank.

    [​IMG]

    [​IMG]

    -Kurt
     
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    • SgtLee511

      SgtLee511 Well-Known Member

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      I had a leaky seal after replacement on my A body Fuel Tank, I wasn't sure why at the time, but I used the original ring after having to empty and drop the tank, and as you state corrected the problem. I have found Bill Rolik Enterprises to be a great vendor as well with good products, I will continue to use him as a parts source.
       
    • moparjohnny

      moparjohnny FBBO Gold Member FBBO Gold Member

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      did you try his sending unit as well,thanks for info very valuable,i need a sending unit and locking ring that is good,i will order his locking ring. thanks
       
    • cudak888

      cudak888 Well-Known Member

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      No idea if his sender is any different than the Spectra/Dorman. Can ask.

      -Kurt
       
    • moparedtn

      moparedtn Ed on the Ridge FBBO Gold Member

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    • cudak888

      cudak888 Well-Known Member

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      Your thread would have made it much easier for me had it come up in my searches; it never did. Burns me up how some of the better threads on this forum never seem to get indexed by Google. Or, for that matter, the search function here in the forum.

      -Kurt
       
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      • themechanic

        themechanic Oklahoma is OK FBBO Gold Member

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        Nice article.

        One more tip. If your tank is nice put something under it to drop it on to protect the finish instead of dragging it across the driveway. Ask me how I learned this.

        Sometimes searching forbbodiesonly and your search term (gas leak, etc) on Google gives better results than using the FBBO search tool.
         
      • cudak888

        cudak888 Well-Known Member

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        I brought mine down with my 4-ton jack, but a transmission jack with the centering tangs/locators removed from the sides ought to bring one down. You have to be super careful though - even though the back of the tank is narrow and tall, it's also long enough to cause it to teeter-totter.

        -Kurt
         
      • moparedtn

        moparedtn Ed on the Ridge FBBO Gold Member

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        The search feature on this site isn't too bad, actually.
        It's how I found my own thread - and the other accompanying one I did as well. :)

        GIS is fine for some things, not so good at coming up with blog results and sites such as this one.
         
      • moparedtn

        moparedtn Ed on the Ridge FBBO Gold Member

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        Being (sadly) well versed to dropping the tank at this point, I get the ass of the car up on stands, drain the tank using a hand pump, then slide under it on a creeper.
        I take the hit and drop the tank on myself, then roll out from under there with it on my chest.
        Tank doesn't get all beat up that way.
         
      • cudak888

        cudak888 Well-Known Member

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        Here's the baffling part about draining the tank - I spent an hour trying to get suction with a hand pump (didn't work), the cover-the-end-of-the-siphon-and-pull method (worked for 30 seconds), and I finally tried the pressure method by plugging the filler neck with a rag and a second tube to blow on, and that didn't work. Oh, and my stand-alone electric fuel pump didn't work either.

        After doing all that, I just said "F this, I'm bringing down the tank, full or not!" Someone had already undercoated and scratched it up before me, so I wasn't too worried - so long as I didn't dent it.

        -Kurt
         
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        • moparedtn

          moparedtn Ed on the Ridge FBBO Gold Member

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          Oh, trust me, I've employed your method more than once. :)

          Yeah, the hand pump thing is maddening. Finally hooked it up to the fuel line coming from the sending unit and managed to get about half the gas outta there.
          As you might imagine, I "wore" quite a bit more of it as I dropped the tank on me and scooted out from under there.
          Hey, I'm HARCORE. *snicker*
           
        • toolmanmike

          toolmanmike Moderator Staff Member FBBO Gold Member

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          I turned this thread into a "sticky" and should remain at the top of the heading.
           
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          • cudak888

            cudak888 Well-Known Member

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            Hey - chances are that if you're not wear the gas on your arm or in your armpit, the tank is empty!

            Thank you!

            -Kurt
             
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            • 69'Net

              69'Net Well-Known Member

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              I have a leaking fuel sender ring as well, I'm about to tackle it. The easiest way to drain a fuel tank I've found is to drop a piece of 1/2" or smaller rubber tubing into the tank and put a little duct tape around the fuel inlet and tube. Then just shoot some compressed air from an air gun into the tank and fuel will pour out of the tubing no problem. No mess, super easy.
               
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              • Glenwood

                Glenwood Well-Known Member

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                Wish I had of thought of that a few weeks ago! I ended up using a marine oil extractor I had from my 32' Sunrunner cruiser. These are not supposed to be used for fuel, however my small hand pump was basically a useless pos.
                extractor.jpg

                The extractor worked great.
                 
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                • Cornpatch MO

                  Cornpatch MO Well-Known Member

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                  Thanks for this thread. good timing for me as I just put in a new sender, and it leaks after the second time I installed it. I did not know about the thin lock ring. I hope my old one is still laying wherever I tossed it !!...........................MO
                   
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                  • 69'Net

                    69'Net Well-Known Member

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                    I had to bend the sides of my locking ring up a bit to make it tighter. Then just made my my own gasket from thicker gasket material. That cured it.
                     
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                    • Cornpatch MO

                      Cornpatch MO Well-Known Member

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                      I found my old original lock ring. It is the thinner one. The thicker one must be an aftermarket improved design................................MO
                       
                    • Cornpatch MO

                      Cornpatch MO Well-Known Member

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                      Has anyone used a sealer on the rubber gasket? Did it do the job and what did you use?.................MO
                       
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