Fuel tank leak on 94fzj80

[1ststatecruiser]

So after non use for about 4 days with full gas and parked on a 35 degree slope . Got back from a short vac and I noticed this am the smell of gas and checked it. It's coming from the rear upper right side of the fuel tank. It's not a steady leak just drops. I removed the gas cap and leak stopped a lot of air came out too. I know i have to drop the tank but just wanted to get more feedback from those who had this issue before i start. thanks much. Some pics I took

This is the top part where the seams meet

Bottom pic

Thanks
Jesse

 

[western flyer]

Any chance your charcoal canister (CC) has failed, causing a high pressure situation in the tank system, then causing the fuel to leak from that hose-tank connection (as the weak link)? I say this because you said the symptoms included that leak stopped when the gas cap was removed and lot of air pressure was released.

IOW, I would go after the high pressure (e.g., CC) and that hose connection.

 

[1ststatecruiser]

I'll inspect it thoroughly and see where the leak is comin from , I hope it's on the hose not tank. Is that the original clamp ? Looks like its been changed . How hard is it to drop the tank? Thanks

 

[concretejungle]

jfz80 has had some crazy gas tank leak issues that still are plaguing him.

 

[jfz80]

Gas tank is not too hard to drop. Doable with rear drive shaft in but much easier with it out of the way.
Two straps, disconnect all hoses from top inspection port under second row carpet, remove filler hose from back of tank and be ready....... drain plug was a saver here if you just filled up.

dont worry you can get it down to under an hour after 4 or 5 times
i had no luck with repairs of all kinds from weld to braze to gas tank repair putty to soap to .....
unfortunately the two used tanks i put in also cracked in same spot.

along with the CC check its outlet breather down inside driver side frame rail and see if its rusted shut

My crack is on top and has repeated itself several times..... just recently there was another two failures posted in same spot. ITs in a 3 directional stamped curve in the tank right where the front steps down and intersects with the slot made for the ebrake cable.

I hope its in the tube for you sake as well.
pretty pictures and some diagnosis started here.....
https://forum.ih8mud.com/80-series-tech/225705-leaking-gas-top-tank.html

 

[Timpanogos Slim]

The vapor pressure when removing the gas cap is pretty much proof positive that your evap system has failed.

Replacing the charcoal canister is generally what fixes that, but you could have a clog somewhere else in the evap system too.

Autozone part VC-120 is a popular replacement for the evap canister. About $40.

 

[concretejungle]

I thought on all vehicles it is normal to hear the vapor escape when taking the gas cap off?!