Just had to drop a tank because the pump stopped working. Do not do this often but usually the tank is clean inside. This time there was a gritty mud/rust-colored deposit that seemed to be on the sides of the tank (could scrape loose with fingenails) and inplaces on the pump/gauge assembly. Small amount of sludge on bottom of tank.

Had not driven much in last two years, been in garage whole time, & gas smelled sour which I have seen before but not this deposit.

Anyone know what it is and should I:

a) ignore it, strainer and filter will take care and is stuck to the side of the tank any way.
b) replace the tank, that stuff is bad news & cannot be removed.
c) something in middle ?

The crude in the tank is only going to clog the filter and may damage the pump. You can have the tank cleaned and sand blasted to remove the loose particles. Use glass beads if your doing this yourself, the glass is easier to clean up after your done.

Looks like the plastic baffles were added before the tank halves were assembled. How do you clean around them ?

What do you think ? Note coating is on rubber and plastic pieces as well. When scraped off it becomes a fine yellow powder (like dust).


My main question is do I just clean off everything and install new pump/strainer/filter or does the coating in the tank need to be cleaned out as well (no idea how to reach past the baffles) or will it just dissolve in time now that the old gas has been removed. I havethe fuel level sender working again after cleaning with tuner cleaner and a piece of wire cleaned out the return and vapor lines.

looks like rust in the pic, can you rinse the tank out to get around the baffles? If the stuff is loose enough it should swirl out of there? Must have been condensation from the empty tank over the last few years?

Is not loose, forms a rough coating on the metal surface of the tank. I can scratch off with fingernails but is attached to the sides.

Had a look in the service site and found the following.

Anyone ever use Phosphoric acid to de-crud a gas tank ? Just slosh it around ?