MTFCA Forum

Sediment bowl was installed on a under-seat gas tank years ago with some thread sealant. What would be the safe procedure for removing now

It would be helpful know what sealant was used. Sealant can make unscrewing it easier or harder depending on type of sealant used. In general, acetone is a powerful solvent and penetrant, and a pint of acetone mixed with a pint of Marvel Mystery Oil and poured into the tank and allowed to sit overnight might be helpful. (Beware of the vapors). Assuming the tank will hold liquid, shut off the fuel valve and pour in the mixture, then put the cap on the tank to retain vapors. DO NOT APPLY HEAT TO THE TANK!

If you determine that the under seat gas tank is to seized to get off from the bottom you’ll need to remove it so you can get a good wrench fit to remove it. You can try it from the bottom but that will depend if you can get a wrench on good enough to turn it. If your not careful you round of the bulb or twist it off in the tank. But the easiest and best way overall is to remove the tank. And that’s if it’s really seized.

Sometimes it helps to break the seal by slightly tightening it a little before loosening it. Is there gas or fumes in the tank? If not a little heat with a Milwaukee heat gun might soften the thread sealant. Jim Patrick

Try heating it with a hair dryer.