Looking for a good Gas resistant/ High pressure Sealant?

Im having a problem sealing a leak that developed on my 04 Tacos Fuel pump sending unit flange,which I have already removed the bed and changed out the fuel pump and replaced the rubber seal with a new one,I prepped the mating surfaces as best I could they were rusty and I sanded them and got all the rust off I could. I also used this Permatex Permashield Gas resistant sealant which I thought will withstand the Gas and Fuel pressures in the tank, I was wrong as soon as the weather heated up I was getting wiffs of raw gas again, and checked the flange and the gas was seeping out of the flange at the same area that I thought was good. I would like to try another sealant before having to go replace the tank itself. Anybody has any good recommendations for a good sealant that might work for my application? The Permatex that I used seemed to have melted away in the area that's seepingit didn't last very long at all. I used this wasn't worth a dam in my opinion.

 

Your leak is where the fuel pump bracket mounts to the tank?/

With ethanol in the gas not only do you need something that does not break down with fuel but alcohol as well plus all the other different additives .

Perhaps something like gorilla hair or something to rework the tank to a nice smooth mating surface ??

 

yes its the mating surface where the fuel pump gets bolted to the top of the tank,this seems to be a reoccurring problem with high mileage gen1s and now im seeing it with some gen2 owners leaking around the flange or mounting areas. I went out and re tightened the little bolts as far as they would go and I am not smelling or seeing any gas yet,but I don't have faith that it will hold up once I top off the gas tank got to do a test to see if it will. If not Im going to try to loosen the bolts and try to squirt some more of that sealant under the gasket lip and pray it holds, if not its either new tank or fill it half way up all the time.

 

You could try doubling up on the gasket .

But being the surface is rough and pitted not even close to a flat surface. It might not help

I see on my stuff the grit and slop gets up on top and is hard to even wash out .