Gas tank leak

All of a sudden , I noticed a leak I the gas tank . Gas is dripping directly down onto drivers side muffler. Car is up on rear jack stands. Battery disconnected. Have not removed the tire carrier yet , but the leak in the area around the strap and the < what looks like a piece of inner tube > is completely saturated . This happened all of a sudden . Any thoughts on the cause of the leak. I siphoned as much gas out as possible? Probably won't get to do much till after Christmas . BUt any thoughts and advised is most welcomed . BIG AL

 Two thoughts...either the vent hose is leaking, which is directly above the ds muffler, OR....the tank has a rust hole in it. If you take the front tank brace off, you'll know real quick if it is a rust issue. But I would first look up towards the vent tube at the top, ds of the tank, about midway front/back and see if the hose is deteriorated....
If it only leaks when the tank is 3/4 or more full, it is the vent hose/tube. If it leaks no matter how much fuel is in it...it's prolly a rust hole...
If you have it mostly drained, you can take a bright light and look down into the tank from the filler, and usually get a good look at the bottom of the tank. If you see any funk standing at the very front edge of the tank, it's prolly rust. Had that problem on the '74. Tried JB Weld on it a couple of times, but it was just too much....I wound up buying a repro tank from Quanta.

|UPDATED|12/20/2013 3:03:58 PM (AZT)|/UPDATED|

Thanks Joel, I only had 4-5 gallons in the tank . I got a feeling it's RUST. About a month ago, I drained the tank, discarded the old gas , ,then flushed the inside 2-3 times with a few gallons on gas,then drained and put in fresh gas .At thet time I noted some rusty looking funking looking deposits on the bottom. When I stirred it up , some would go into suspension in the fresh gas ,that's why I flushed it a few times. Still some rusty colored crap in the tank, just a little here and there. I think it will show rust I when I drop the DS strap. Thanks for the quick. Response. If I don't get a chance HAPPY HOLLIDAYS to you and everyone on this GREAT. Site BIGAL

UPDATE. Finally got to dropping tank and found a pencil size hole. Ready to install new tank. QUESTION. ??? Is it easier to install the sending unit in the tank then then tank into the car OR put the tank in the car and then install the sending unit . Any tips or tricks would be appreciated. Thanks , Big Al. ANY special tool needed to reinstall the cam nut!? USED screwdriver and hammer to remove once the entire tank was out of the car..

|UPDATED|4/7/2014 12:25:12 PM (AZT)|/UPDATED|

I think installing the sender unit is easier on the ground(or bench), myself. Best tool to use to remove/replace the cam-lock is a brass drift, if you do not have the "special tool" for it...which few folks do. A wide, DULL chisel, or flat bladed screwdriver will work too,since it's a new tank, and there are no fuel fumes in it to explode if you get a spark from the chisel/screwdriver....which is also the best reason to use a brass drift....it will not spark. Put some grease on the o-ring seal, and that will make it a little easier to seal. A little grease between the cam-lock and the sender top will also help.

GREASE was the answer. Cam nut went on without any $&@#%^<€¥? Words and now busted knuckles. Small hammer and a little dull chisel . Joel you rock Once again. Hopefully get the tank back in this weekend , if I'm not chasing the Easter Bunny. Thanks. Big Al