filler neck and spectra tank

[killnine]

So I replaced my old rotting fuel tank with a new spectra, and it just isn't right.
It's worked for me for a while now but it is sort of connected in a cockeyed fashion, and it's causing fuel to leak out of the grommet. Or the grommet is just wrong somehow.
When I installed it, I had a really hard time getting the neck into the grommet like most people. However, I also couldn't quite get the neck as far back as it should be. It is pushed forward towards the engine bay enough that the big rubber seal that it goes through is being pushed forward as well and you can tell that it's just wrong. I think this is deforming the grommet enough to make it leak. Of course after I got it in I certainly didn't want to redo it, but now I want to solve the problem. I'm thinking that possibly something is causing the tank to not sit as far back as it should. I put some tar paper in there like the original had, but I can't imagine it's so thick that it would cause an issue. Anyone have this problem? Any ideas before I just blindly tear it apart?

 

[barbee6043]

so exactly what model ole mopar are ya workin on!??????
did ya buy a new grommet???? or reuse the one that's maybe 50 years old? it helps a bunch to clean up the filler tube before restallin. also lube the grommet with baby oil, maybe vasolene, KY???? that tank fits in there pretty much in a certain place. like you say should not be **** eyed. looks like you will have to loosen the j bolt and strap and repostion, or also buy new rubber filler neck grommet. are you sure its not leaking at the pickup tube.? the repop retainer ring isn't as thick as the original one, and this can cause a leak there too. hope this helps.....

 

[killnine]

so exactly what model ole mopar are ya workin on!??????
did ya buy a new grommet???? or reuse the one that's maybe 50 years old? it helps a bunch to clean up the filler tube before restallin. also lube the grommet with baby oil, maybe vasolene, KY???? that tank fits in there pretty much in a certain place. like you say should not be **** eyed. looks like you will have to loosen the j bolt and strap and repostion, or also buy new rubber filler neck grommet. are you sure its not leaking at the pickup tube.? the repop retainer ring isn't as thick as the original one, and this can cause a leak there too. hope this helps.....

Model is in my sig.
Yeah I used the old retaining ring. It's leaking from the grommet for sure. It's the old grommet, because I couldn't get the tube into the new grommet. I've got another new grommet just in case this new one fits better (from a different seller). It could be leaking because of the old grommet, but the fact that it also is pushing the neck so far forward really bugs me. Maybe half of the problem was that I put the tank in first, and then tried to put the neck in, then tightened it down. It seems the proper way might be to put the neck in the trunk then try to get the tank onto the neck, then tighten everything down. Or maybe the right way is to take it to the shop where they have more than one or two tired old men.

 

[Dartnut]

Mine fit great in my '74 Dart Sport.
I used a new filler rubber grommet, lubed it with WD-40, and slipped it onto the tank. I re-used the top pad off my old tank which is about 1/8" thick.
Then i lifted the tank into position, and installed the straps and j-bolts.
I then slipped the filler neck into the new grommet from inside the trunk after lubing it again with a light coating of WD-40 and slipping the trunk floor grommet 1/3 the way up the filler neck beforehand.
It's not hard to slip it in and wrestle it in place if it's lubed up a little.
The important step is that you have to rotate the neck until it is in the right position where it's clocked correctly in relation to the quarter panel mounting surface.
I used a new pickup/sending unit when i installed the tank.
It has zero leaks, squeaks, or rattles.
The tank should fit to the trunk floor snugly, and it only goes in one way.
My only thought is that you don't have the filler neck in right, it's bent, or the rubber grommet at the top of the tank is old and leaking.
Check to see if it's the seal on the pickup/sending unit, it's possible to leak there too if it's installed incorrectly.
If the hole in the trunk floor lines up pretty good with the hole in the tank, it's positioned correctly.
Good luck and let us know how it goes........

 

[grumpuscreature]

I would loosen the tank straps a bit and see if I could get things straightened out. When everything is lining up to suit you, stick a floor jack with a block of wood under the tank and put just enough pressure on the tank to hold it in place. Then tighten the straps, release the jack, and see what you got...

 

[killnine]

I would loosen the tank straps a bit and see if I could get things straightened out. When everything is lining up to suit you, stick a floor jack with a block of wood under the tank and put just enough pressure on the tank to hold it in place. Then tighten the straps, release the jack, and see what you got...

Yep. I'll try to reposition it next weekend. I remember trying to get the neck in the new grommet before when it was lubed with I think power steering fluid was like putting a square peg in a round hole. I pulled some arm muscles that day. Sometimes the second time is the charm. Mostly it's the lack of leverage to push on the neck with it anywhere near the car.