what is the best way to clean fuel tanks that have been sitting for 5 years? can it be done without dropping the tanks?

 

don't know that there's any simple way to clean out an old tank other than drop it and clean it. first question is do the tanks have fuel in them now? if they do, after 5 years my bet is the fuel is foul and i'm not sure that you could siphon enough out to keep from getting gunk in the fuel lines, filter, et cetera. maybe somebody else on the site has a better way to go about it, but that's the best I know. it's not really all that bad getting empty tanks out, just takes time, muscle and patience. one option is to undo the bed bolts and lift the bed off and out of the way. hope this helps some.

speedrdr

 

txaggiegolfer,
Welcome to FTE and the IDI diesel forum.

Before I worried about cleaning the tanks, I would try to siphon out a couple gallons of fuel from each tank.

If you find rusty fuel or fuel with black algae growning in it, you will need to clean or replace the tanks.

If the fuel looks OK, I would mix in some fresh fuel with an addative like Diesel Kleen and run it.