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Charcoal Canister on rebuild

Discussion in 'Intermediate CJ-5/6/7/8' started by BrettM0352, Dec 23, 2010.

  1. Sep 24, 2019
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    I don't see how the expansion tank is needed if there is no vapor recovery. I would say that vapor recovery was there but parts for it have been removed.

    Your tank should have a nipple at each corner, one to each of the nipples that feeds to the bottom of the expansion tank. There is then a nipple that opens high in the expansion tank, that has to go to a vent of some sort, assuming you are using a sealed gas cap.
    There is a limit fill / check valve in the '72 drawing, but I don't know if that's what's used on the earlier models. There must have been something under the hood like the '72 valve that accepted vapors from the expansion tank.
     
  2. Sep 24, 2019
    jzeber

    jzeber Well-Known Member 2022 Sponsor

    Morgan Hill, Ca
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    I beleive this was a California vehicle from the start. Wondering if Ca. asked for smog parts prior to 72'. I have a hose from the vent side of the pick up to the canister. 2 other hoses from the tank to the canister, 1 cut hose that goes nowhere and another that appears went to the return line but has been cut. Very confusing. Wondering if I plumbed one wrong and the tank is not venting. That seems like it would let it run for a while then cut off like it has been doing.
     
  3. Sep 24, 2019
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    You looked at the pics from the '72 TSM at the top of the thread? Seems very likely to me that CA delivery '71 would have that same design tank and vapor recovery plumbing. From the Jeep parts dept, I do not recall there being another tank design in that era (ie a '70-71 style) but the '73 or later tank is different. For the later design, Jeep replaced the vent at each corner with some internal plumbing (and added expansion volume?) and did away with the expansion tank. These tanks have two small vents for vapor. Any return hose from the fuel pump would have gone to the extra nipple in the fuel pickup and sender plate.

    If you have vents at the corners of the tank that are open, they will spew fuel when you fill the tank.

    I don't have any reference material for a 1971 CJ - maybe someone else on here does.
     
  4. Sep 24, 2019
    jzeber

    jzeber Well-Known Member 2022 Sponsor

    Morgan Hill, Ca
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    CJ5 Tank.jpg Thank you very much for the info. I believe I have an aftermarket tank but here is how it is plumbed right now. There are 3 hoses coming out of the tank itself and one coming from the sender plate.
    Sorry for the chicken scratch.
     
  5. Sep 24, 2019
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Pic of the tank would help. The nipple on the sender definitely does not go to the expansion tank - it's either capped or used for the return from the fuel pump. I have never seen a tank with three vent nipples; either two (next to each other) or four, one from each corner, as in the '72 TSM drawing.

    This is the '73-75 tank - it was used with a plastic liquid check valve and a charcoal canister, not the expansion tank and fill / check valve shown in the '72 TSM. Is this what you have? You sure the front corner is not plugged?

    upload_2019-9-24_20-9-58.png
     
  6. Sep 24, 2019
    jzeber

    jzeber Well-Known Member 2022 Sponsor

    Morgan Hill, Ca
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    Mine is square and boxy. It has 2 nipples near the driver rear corner and one in driver front corner. The one from the sender plate has always been there. The return from the pump is cut and plugged.
    Unfortunately the tank is a beast to remove so getting a pic of the top is almost impossible. I'm pretty sure it is an aftermarket 20+ gallon steel tank.
    Thanks for the help
     
  7. Sep 26, 2019
    jzeber

    jzeber Well-Known Member 2022 Sponsor

    Morgan Hill, Ca
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    A quick update. I changed my fuel pump yesterday and it runs great. I am not sure what is going on with the canister but I am going to leave it the way it is for now.
    Thanks for all of the input.
     
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