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Fuel Tank Installation

Discussion in 'Early CJ5 and CJ6 Tech' started by Jonbbrew, Nov 30, 2020.

  1. Jonbbrew

    Jonbbrew Member

    Hello all! Hope y’all have a great Thanksgiving!

    I have a new tank on order and will be here tomorrow. The previous one rusted out on the bottom where is that against the floor. Is it metal to metal normally or is there supposed to be some sort of padding or material in between metal to metal contact?
     
  2. dunno, but sand/dirt got under mine and destroyed it, had to repair and added some padding, no trouble since. would recommend some kind of foam, think there was originally a felt pad under it
     
    Jonbbrew likes this.
  3. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    I think there was something in there. When I installed one of these tanks in a later Jeep, I put some sections of broken black rubber bungee cords between the tank and the body.
     
  4. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    There were factory (wood?) spacers in there. I used 3/16" uhmw which centered the filler in the hole very nicely.
     
  5. mike starck

    mike starck Member

    also used uhmw strips between tank and floor. 3/16 " sounds good.Mcmaster-carr if not available local.
     
  6. i epoxied strips of memory foam (i think, unsure exact material) under it, about 1/4 inch thick.
     
  7. Jonbbrew

    Jonbbrew Member

    Thanks all. Good tip. I wasnt sure what i was going to use. One thing i am concerned about is that since my jeep is a Frankie, i dont know what is typical. I assume any with a V6 has dual exhausts where one of the mufflers sits right below the tank. So wondering if heat is an issue with these setups? Also considering some sort of reflective heat shield on the bottom of the body between the tank.
     
  8. i dont have anything like that, but fuel line is next to exhaust (under tank) and i dont have problems. will look at it later.
     
  9. also, used to live around there, think i have some relatives in paso...
     
    Jonbbrew likes this.
  10. Jw60

    Jw60 That guy 2024 Sponsor 2023 Sponsor 2022 Sponsor

    The muffler heat should be ok with the gap between the tank and body and the mufflers spaced from the underside of the body.
    My 4.3 has a muffler under the tank and it's maybe 2" from the tub. It can get hot if there is an issue with the engine running off time or lean.
    When you box in the mufflers to protect them from rocks is when it's an issue.
    Also keep the fuel lines away from heat as the fuel isn't able to dissipate the heat over it's mass when in a suction line and is more likely to boil there.
     
    Jonbbrew likes this.
  11. Jonbbrew

    Jonbbrew Member

    Cool. Been here for almost 30 years. Besides the California craziness we love it here. Also home of Advanced Adapters.
     
  12. Jonbbrew

    Jonbbrew Member

    7A8A81D2-6ADD-482A-9183-51CC7BC85F76.jpeg
    I do have an old pack around the mufflers. Just being extra cautious I guess since I have found so many unsafe hacks from PO.
     
  13. Jw60

    Jw60 That guy 2024 Sponsor 2023 Sponsor 2022 Sponsor

    I wouldn't use the insulation. It will hold water from the road and rot the mufflers. Just let it hang out in the breeze and i don't think you will have an issue.
     
  14. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    If you need to block heat from the exhaust, a plain piece of sheet steel with an air gap on both sides works well.
     
    dozerjim and Jonbbrew like this.
  15. Jw60

    Jw60 That guy 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Here is what I have been running. Looks like my mufflers are a little farther forward. My floors are 1/8" plate but the tank is only insulated by a layer of dust.
    If it does have heat issues a thin sheet with airflow between it and the body is best.
    Wider sheets of uhmw (ultra high machine workability) plastic or a old polyethylene carving board between the body and fuel tank should help.

    [​IMG]20201130_163843 by Joe with a jeep, on Flickr

    [​IMG]20201130_163953 by Joe with a jeep, on Flickr
     
  16. I have a V6 , With duel exhaust, ..... and I sheet metal screwed a piece of aluminum flashing from the hardware store, up under the cab, between the tank and the exhaust... it TOTALLY reflects all heat from the cab floor and the gas tank.... and can't be seen from outside, unless you crawl under the body.....
     
  17. and some wonder why we moved out...
     
  18. Jonbbrew

    Jonbbrew Member

    From the PO and I assume these have been on for years if not decades. Being a California rig it’s pretty dry.something to consider though but I wonder if the heat would always evaporate any moisture (?)
     
  19. Jonbbrew

    Jonbbrew Member

    Indeed. Born and raised but it’s really getting way to much. Planning our exit.
     
  20. Jonbbrew

    Jonbbrew Member

    My new tank has two fittings in the bottom. What’s the second one for?