correct way to install toilet tank bolts

Remember to alternate tightening as you go until the tank sits level with the bowl. Finally, put the tank back into position and tighten all of the bolts.

Find the gasket and pull it away from the bottom of the tank. I've tried toilet-bowl cleaners that 'clean under the rim,' using a soft, flexible brush, and even put bleach up into that, but nothing seems to work. Take the tank off of the bowl and turn it upside down. I don't know what a cross-section of a toilet looks like, but I suspect the smell is coming from under the lip where the water comes in to fill the bowl. (We keep the lid down when not in use to keep our cats out.) The tank doesn't seem to have any problem, and the base is clean and grouted to the tile. It seems to be coming from the bowl, as the smell is stongest when the lid is up. There was a lot of dried urine, which I thought was the source of the odor, but even when that toilet is as clean as I can get it, even now, six months later, it STILL smells. I went to my local install new rubber gasket and new hardware to toilet tank. Most toilets are installed with a wax ring that fits over the bottom drain opening (the horn) to create a seal between the bottom of the toilet and the drain pipe. Knowing that the previous owners had young twin boys who had potty-trained while living here, we replaced the toilet seats, and I scrubbed and bleached under the fittings, in every crevise behind and under the toilet, and everywhere I could reach. I said to myself, no way its leaking from the bolt. We bought our house in January, and I've been trying ever since to find the source of a sewage odor from the m/b toilet.

I've been married 17 years, have lived in numerous apartments and houses, and have cleaned plenty of toilets, but this is the first time I've come across this problem:

Correct way to install toilet tank bolts