I had the same problem, the tank was so rusted, it would plug up with chunks of rust so bad I couldn't even leave the house. It wouldn't get the filters dirty, because nothing got there. I don't know what year your truck is. (even though you probably have it in here somewhere), but my 53 has a very small outlet in the tank, and it gets plugged very easily. You can fight it or buy a new one. It would have cost more to get mine boiled out and sealed than a new one. So for me it was simple. You gotta do one or the other, you will most likely never get the tank clean in place.
