Beginning to Keg Q's

Getting ready to keg for the first time. I'm cleaning the keg with PBW, and turned it upside down to set for a while. While upside down, I'm getting the tiniest of water leaking - pretty sure around the oval lid. I've replaced the rubber seal, and still getting a small leak.

My 1st question: Is it safe to assume that gas will leak out also, or will the pressure from the Co2 apply pressure on the inside of the oval lid and help form a seal??

I know I could put some Co2 in the tank to find out for sure if it leaks gas - but I don't have my mini kegerator lines switched from pony to corny.

More than likely you are correct is assuming that the lid o-ring seal is leaking due to the fact that it has not been "set" with CO2 pressure. A great method of checking for leaks is to fill up your batch tub, pressurize a keg to 25 psi or so and then submerge the keg into the tub and rotate it around looking for bubbles. This method will reveal even the smallest of leaks.

John