Fuel Tank Leaking

ArnieJr

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Good evening,
While spending some quality time underneath my Chrysler today (rear brakes, yay!), I noticed gas leaking from my tank. I've been able to narrow it down to the vent tube where it comes out of the tank. The left hose bends easily whereas the right does not, so I'm wondering if something broke inside. I've never seen the whole this disassembled, so I don't know if this is a tube that runs through that hose and something cracked inside of it or what's going on and I don't want to go into it blind. The service manual only tells how to remove and install the tank, kinda wanna void that if at all possible! Yeah, I'm looking for an easy, but safe, fix.
That said, can someone just give me some ideas as to what may be causing that leak before I start taking stuff apart and have gasoline gushing out?
This is for a 69 Chrysler 300 Coupe.
 
If it's just the tube itself, you can possible take it to a radiator shop and see if they can re-solder it back together. But that requires tank removal, which can be reasonably easy if the tank is EMPTY first. You probably need to replace the rubber hose on the tank fuel outlet anyway (age and ethanol'd fuel issues). Plus the other rubber hoses back there. While it's out, a new seal where the filler neck goes in too. Then the electrical connection to the sender and the small special clamp on that outlet fuel line (which grounds the tank so the dash fuel gauge works). Then the bolts at the rear of the strap mounts, for which you'll need a floor jack under the tank or have the car on an overhead lift with probably two assistants to "catch it" as the straps are loosened. Save any insulator strips/pads which might be in place, too, for re-installation. Depending upon your particular situation, this might also be something best left to "a shop" to do as the tanks weight about 25-30lbs empty and can be bulky to handle by one' self. BTAIM

The radiator shop might want to also clean the tank, for good measure. Maybe even "seal it" inside. Your judgment call, but the longevity of the sealing operation can depend upon how well the cleaning operation is done, by observation. If the car has been in continued use, this might be skipped if the car has not sat for an extended period of time. Your judgment call.

When the repair is complete, reverse to re-install. Initially re-fill the tank with about 5 gallons of gas to check the gauge's "1/4th tanik" calibration.

DO inspect the rest of the lines under the car with the tank out. If you need new ones, www.inlinetube.com and others might supply them pre-bent and ready to install. Even stainless steel versions, too.

Just some thoughts,
CBODY67
 
One of my tubes was loose and leaking. I used this at the joint where the tube leaves the tank. https://www.jbweld.com/product/tankweld

Make sure you spend plenty of time getting the surfaces of the tank and the tube thoroughly clean and scuffed up.

Perfect.
IMG_1701.JPG
 
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Note that the surface on the epoxy putty that almost looks like fabric is in fact my multiple fingerprints as I worked the stuff into place.

It cures in an hour into a rock-hard condition.
 
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I’d personally replace the tank for piece of mind, if you go this route remember to keep your original lock ring and gasket for the sending unit for your new tank. The new lock rings and gaskets are to thin and leak. These tanks by spectra are good quality and made in canada. Just bought one for my 70Newport.
Product
 
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