Gas tank leak, likely EVAP issues
 

Hey guys, I'm having a major issue, this on a 91 with a 20 gallon steel tank: About 3 months ago my gas tank formed a tiny crack on the bottom with no cause to claim. Picked one up at a JY and had a shop put it in. Because I picked it up I inspected and saw it was rust free and clean. So - about $300 and a long JY drive. Well now this tank has spawned a leak in the same spot (haven't pulled the shield but it dripping from roughly the same area). The past 6 months or so I noticed a ton of pressure being released when loosening the gas cap, after a fill up I have had times the cabin smelled gasy. With the new tank I started getting this "pop/bang" noise; it was so loud once I though someone hit me...anyways my assumption is the noise was the tank flexing somehow from pressure in the tank, as I don't hear it now with it leaking. And the possibility i hypothesize is no tank venting is happening to let vapors out. Is it possible that pressure is building so much in the tank that it is causing a weak spot to stress and crack? There are no line leaks, no leaks at the pump ring, just the bottom on the drivers side out of a hole in the shield. Really need to pinpoint this before I put a new tank in just to crack again...thanks in advance.

Wow nothing? Ok, well anyone have experience with Evap canisters going bad at least, any tips or info on that?

Not a load of expertise here. Changed a number of those pumps and have a general idea of the evap function. It's the same general setup as 87-90, but there were lots of changes there, they may have added an evap solonoid in 91, clueless there, here.

So you have done some "knoggen-poken", and verified it's not the O ring seal for the pump assembly, or a line that you can see. Two lines forward are fuel delivery and return, (to the pump plate). Then a third, vent goes up top right? I suppose If I could isolate it to the upper vent, I'd contact the people who installed it and see what they say.

A question, you are not topping it off are you? Gotta wonder if a flooded canister can vent right. Google there maybe.

Alex, I'll take smashed, pinched and leaking vent tube, due to sloppy install for 1000. Or , can you see a nipple for the line?

Well yeah, I'm guilty of topping off over the summer because of the lower gas prices. Usually only a click or two. But I wouldn't be surprised if it's the evap because I was topping it off. I've never done it except this year, and go figure now I have replaced two gas tanks in less than four months...so you can all tell me off if you like. I didn't think topping off was the best idea...but really I'm just looking for tips and help on swapping the tank and servicing/replacing the evap, and of course calling put to anyone that had the same or simular issue.