I have one tire that is not holding air. After checking it I found out the air was leaking from the O-ring. Or at least where the rims come together. I tried to separate both pieces from the tire but was unsuccessful. I was able to get one piece broken from the bead but the other was not coming off. Some one used tire slime to “fix” the leak and it just nastied up everything inside. The surfaces where the two pieces meet was rusty and nasty. I cleaned the surfaces up real well and down to bare metal. I painted the surfaces to prevent more rust. The O-ring was intact and I did not feel any weakened areas. It was covered it nasty slime and rust but I was able to clean it. I re-installed everything and found a small air leak (unlike the big one from before). I figured I did not tighten the bolts down enough so as I started to apply torque all the air blew out. I though I destroyed the O-ring. I unbolted the rims and pulled the O-ring out. It appeared to be in great shape and a complete circle like it was when I installed it. So, what am I doing what and what could be the problem?