Clean Your Tank II

It started innocently enough -- the "dual function reservoir" on my 1989 Ford F-150 got plugged up with tarry residues from the gas and the rear tank no longer worked. I didn't really have the time or money to deal with it, so I just continued to drive using the front tank only. It actually took me a long time to figure out that the problem wasn't with the rear fuel pump, which was the obvious (and wrong!) conclusion. A gummed-up fuel tank selector valve actually sends gas from the front fuel pump to the engine, then returns it to the rear tank, which eventually overflows. No wonder my gas mileage was so abysmal!

Eventually I began to have driveability problems, which I attributed to "bad gas." What I had yet to realize is that there is no "good gas." Gasoline is a terrible fuel for internal combustion engines. The tarry residues that gummed up my fuel system are a ticking time-bomb that will eventually claim any gasoline (or diesel) engine. If your car or truck has a diesel engine, Do It Yourself Biodiesel conversion is easier than you might think and well worth considering. In any case, you need to get the injector-fouling glop out of your tank.

In Clean Your Fuel Tank!, I explained how you can effectively clean your tank using commonly available household products. This is a reasonable alternative if you can't find a local shop to clean the tank, or if you just want to save some money over professional cleaning or a new tank. If you have a little background in chemistry, you won't find anything too surprising there, but others may find it a little disturbing to think about pouring Drano in their gas tank.

As I continued with my repair saga, I had to do a little research on which of the many new flavors of Permatex would be best to reconstruct the discontinued grommet that holds the anti-rollover vent in place and the gaskets for the fuel tank lock rings. (It's Permatex Ultra Rubber Gasket Sealant & Dressing.) Searching for "rust remover" in order to find the link for Permatex Naval Jelly, I happened upon the KBS Fuel Tank Sealer Kit.

If you're uncomfortable pouring corrosive chemicals into your gas tank just because some conspiracy theory wing-nut on the internet says it's a good idea, I can't blame you. On the other hand, this kit provides you with an alternative set of "store-bought" corrosive chemicals and a little confirmation if you decide to go the cheaper route. The kit consist of three products, which are also available separately:

• AquaKlean (gallon)       Also available in quarts, this is a heavy-duty degreaser. So is Drano.
• RustBlast (gallon)       Also available in quarts, this is a rust remover and metal etch like naval jelly. Rust Blast also leaves a zinc phosphate residue, so failure to use this may void any KBS warranties.
• Gold Standard       is the special tank sealer coating which seems to be available only in the tank Sealer Kits, at least through Amazon.com. If your tank is already leaking, I'd recommend a new tank.
• RustSeal (gallon)      
      Also available in quarts, and pints, the silver color contains metal filler for pitted surfaces. "RustSeal is so indestructibly tough it won't crack, blister or peel even when exposed to the most aggressive chemicals." Should be fine in your tank.(?)

After agonizing over the pros and cons of coating my tank, I decided that the possibility of large amounts of rust getting through my fuel filter was just too troubling. Better to completely rustproof the tank. Replacing the steel tank with polypropylene wasn't a particularly viable option in this case since the exhaust pipe comes too close to the tank. This option also typically involves replacing the fuel pump hanger, which may attach to polypropylene tanks differently than to steel tanks.