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@^%$ new gas tank STILL leaks!

You guys had me worried about my new gas tank so i took it down and filled it with about 8 gallons of Diesel fuel,plug'ed up the lines,tipped on end and left it for a few hours....No leak
 
I would not even try any type of sealant on the rubber.
I'm wondering if that wasn't a problem this last time.
I know it is obvious, but the rubber should do the trick.
I've never had one leak with good (nitrile ?) rubber and a tight, proper lock on the ring.

Good thread. Here's an alternative to using the thicker gauge lock ring:

I recently removed a non-leaking sender to make an adjustment on the float arm. After re-installing the gasket it leaked with a full tank. Took a close look at how the ring was seated and it was actually the rubber gasket that had moved out of position. There is a narrow sealing ring on the tank, and while twisting the lock ring the gasket can move off-center.

After re-positioning the gasket and carefully seating the ring, the same gasket did not leak.

The gasket which came with my Spectra tank had a thickness of 2mm or 5/64". I found a 12"x12" sheet of 3/32" nitrile or Buna-N (which has good fuel resistance), which is approx. 2.4mm. Cost $10 incl. shipping. You can cut your own slightly over-size gasket which will not slop around as much during assembly, and the extra 0.4mm will help with the seal-off.

Also, here is the amount I bent the float arm in my 67 Coronet (previously it was straight). At 1/8 reading on the fuel gauge it took 13 gal to fill, meaning there was approx. 6 gal left. This calibration took 3 attempts including the familiar leaking gasket ordeal, so maybe this will help others.

FullSizeR.jpg
 
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Good thread. Here's an alternative to using the thicker gauge lock ring:

I recently removed a non-leaking sender to make an adjustment on the float arm. After re-installing the gasket it leaked with a full tank. Took a close look at how the ring was seated and it was actually the rubber gasket that had moved out of position. There is a narrow sealing ring on the tank, and while twisting the lock ring the gasket can move off-center.

After re-positioning the gasket and carefully seating the ring, the same gasket did not leak.

The gasket which came with my Spectra tank had a thickness of 2mm or 5/64". I found a 12"x12" sheet of 3/32" nitrile or Buna-N (which has good fuel resistance), which is approx. 2.4mm. Cost $10 incl. shipping. You can cut your own slightly over-size gasket which will not slop around as much during assembly, and the extra 0.4mm will help with the seal-off.

Also, here is the amount I bent the float arm in my 67 Coronet (previously it was straight). At 1/8 reading on the fuel gauge it took 13 gal to fill, meaning there was approx. 6 gal left. This calibration took 3 attempts including the familiar leaking gasket ordeal, so maybe this will help others.

View attachment 370298
Wow, were you pulling the tank every time or did you manage to just get the sender out with the tank still in the car?
 
Tank in-car. It took some patience to fish out the sender from over the rear end. I used a mirror and trouble light to re-install. Admittedly pulling the tank makes the sender part easier but you pick your poison I guess!
 
Tank in-car. It took some patience to fish out the sender from over the rear end. I used a mirror and trouble light to re-install. Admittedly pulling the tank makes the sender part easier but you pick your poison I guess!
Color me impressed. :)
If I ever find a good original Mopar sending unit, I'll go after mine again one day.
 
Moparmitch has nos lock rings if needed.
 
Good thread. Here's an alternative to using the thicker gauge lock ring:

I recently removed a non-leaking sender to make an adjustment on the float arm. After re-installing the gasket it leaked with a full tank. Took a close look at how the ring was seated and it was actually the rubber gasket that had moved out of position. There is a narrow sealing ring on the tank, and while twisting the lock ring the gasket can move off-center.

After re-positioning the gasket and carefully seating the ring, the same gasket did not leak.

The gasket which came with my Spectra tank had a thickness of 2mm or 5/64". I found a 12"x12" sheet of 3/32" nitrile or Buna-N (which has good fuel resistance), which is approx. 2.4mm. Cost $10 incl. shipping. You can cut your own slightly over-size gasket which will not slop around as much during assembly, and the extra 0.4mm will help with the seal-off.

Also, here is the amount I bent the float arm in my 67 Coronet (previously it was straight). At 1/8 reading on the fuel gauge it took 13 gal to fill, meaning there was approx. 6 gal left. This calibration took 3 attempts including the familiar leaking gasket ordeal, so maybe this will help others.

View attachment 370298

Thanks for the info on the nitrile rubber. Used it yesterday when replacing my gas tank. Replaced sending unit couple months ago and it leaked badly. The locking ring and gasket provided with the sending unit was junk obviously. Got a NOS locking ring from "moparedtn"...thanks again man! And cut my own gasket from the nitrile rubber recommended by "69Runner"...thanks. Both those combinations ensured a snug fit and NO LEAKS.

65 Coronet Sending Unit.jpg
 
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Wow, were you pulling the tank every time or did you manage to just get the sender out with the tank still in the car?
Thanks for the info on the nitrile rubber. Used it yesterday when replacing my gas tank. Replaced sending unit couple months ago and it leaked badly. The locking ring and gasket provided with the sending unit was junk obviously. Got a NOS locking ring from "moparedtn"...thanks again man! And cut my own gasket from the nitrile rubber recommended by "69Runner"...thanks. Both those combinations ensured a snug fit and NO LEAKS.

View attachment 372134
Awesome!
Hey, my pleasure sir. Just paying it forward like MoparMitch instructed me to.
He da man. I just hang out here. :)

BTW, what did you disagree with in one of my prior posts, Dennis H ?
 
Where did you get the nitrile sheet from?
I found it on eBay. Give me a sec and I will find the seller.

It is zorotools. Look up 4050-3/32 buna. 5.35 + 5 shipping right now. One left.
 
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10-4. This will come in handy at work since I'm working on old cars and dealing with reproduction parts which as you know SUCK on fitment.
 
I found it on eBay. Give me a sec and I will find the seller.

It is zorotools. Look up 4050-3/32 buna. 5.35 + 5 shipping right now. One left.

That's where I orded 12" x 12" sheet on ebay. Had it in 3 days...can't go wrong.
 
Well, I managed to get about 7 gallons siphoned out before it stopped working, so I set about pulling the tank.
Wound up wearing quite a bit of it, as there appeared to be another 4 gallons or so in there.:mad:
The sending unit looks like hell. I don't know if I even want to try to clean up things and try again or just scrap the whole damn mess...
Next time use the pick-up tube itsself, put about a 7or8 ft. hose on it and let it go in a oil change pan, put it back in a can. it will get all but about a half pint of the gas. started doing this about 30 yrs ago when I dumped about 2 gal. in my lap, no more!!! Dave.
 
An easier way to calibrate the sender and fitment of the gasket/sender unit would be out of the car - but make a timber frame to support the tank level, as if it were in the car. Just a thought...that's how I will attempt this next time. :thumbsup:
 
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