The Low Down, Dirty Gas Tank Blues!

[floorit426]

I replaced the gas tank, in my 'Cuda, over the winter. Everything seemed to be okay, until I filled it the other night. I have a substantial leak where the sending unit fastens in. I snaked a rod up to the collar and gave it a couple of whacks, no dice. Now, I have to remove the rear valance, muffler, and shield, just to access it. I think I installed it, correctly, using a new gasket and locking ring. I'm hoping I can fix it, without pulling the tank (car has vapor recovery).

What a PITA! Lesson learned, I should've filled it, before install, checked it, then drained it.

[jimynick]

The problem seems to be with the new repro locking rings, as they're thinner than the oem one and don't seal tight enough accordingly. Do you have the original lock ring? There's been discussions about this before, so a wee search might help. Good luck   

[Topcat]

Had it happen to me as well. 

Except I did use the OEM ring, and it leaked...Really Bad

Bought a repro on Amazon and it fixed the problem.

[MEK-Dangerous]

The problem seems to be with the new repro locking rings, as they're thinner than the oem one and don't seal tight enough accordingly. Do you have the original lock ring? There's been discussions about this before, so a wee search might help. Good luck   

I think you nailed it.

I had a 70 Challenger, so it was easier for me. I bought a new sending unit, so I thought, why not buy a new locking ring and gasket?  BIG mistake.

[Jay Bee]

Check out the lock ring/ gasket set from DMT, way better than what you get with replacement sending units. Just FYI, I've never had to remove anything on my car when replacing the sending unit, but I don't have any resonators (or mufflers) beside the tank.

[floorit426]

Thanks, for the tip! It's been ordered.