Farmerjon wrote:

I'm having trouble with connection and getting pictures to upload,but you can see I don't have much space to work in.
Handy9
What did you use to clean it?
It is still not clear exactly where the leak is . Is it at the bottom of the tank in this picture or is it in the pipe and valve on the outside ? Is it possible that is leaking from the top at the toilet connection . The black tank seems to indicate it is ABS plastic . That would be good as ABS is repairable with ABS cement .You can test with MEK to see if it dissolves the plastic . The white ring on the outside is not a seal , just decorative and to close up the hole from the elements . If not removing the tank you will have to at least do as Covered Wagon suggests and cut a larger access hole . From the picture I'm guessing that the 3" pipe going into the tank fitting is glued and not threaded .Good luck .