[Brian.]

Originally Posted by Nickj

The steel tanks also have issues with ethanol, it absorbs water, the water drips out of suspension and sinks to the bottom where it can cause corrosion at the bottom of the tank.... which is where it hinges.

Whichever or whatever you get clean the tank out (steel or plastic) ratttle a generous handful of steel nuts around in it for a while, reclean and then seal with ethanol safe epoxy.