i pulled my fuel tank months ago and had it hottanked to get the crud out of it. the fuel sender was pulled in the process and after reinstalling it in the tank and the tank in the car, gas leaks when the level reaches the height of the sender. i reinstalled the same o-ring (maybe a bad idea?) and the retaining ring. i didn't see any indication of a problem prior to reinstalling but the gas leak is obvious i'm off track. any help?

Well, It's likely a new O-ring is in order. When you go to install it, check the surfaces the O-ring will bear against for smoothness. Correct any inperfections on the sealing sufaces as necessary. As I remember, the sender needs a bit of TLC to keep it centered in the tank opening. Use a little bit of silicone grease on the O-ring before you put it on.

What condition are all the vent hoses in? Could be one has cracked. I've got a similar problem, if I fill the tank too full it leaks. I'm planning to drop the tank, get it boiled out & sealed, and replace all the hoses.

ken, when i dropped the tank, i replaced all the hoses to the tank. the only thing that was left i did not replace was the boot from the filler neck. either way, i found the problem at a gas station a while back while filling the car. i could see it coming from the sending unit.