Just got a used challanger VI keg and I replaced the o rings on it. Now when I put the lid on and flip the latch it fits loose. I bought the standard oring set for ball lock kegs from my LHBS. I filled the keg with CO2 and it held pressure for about 2 hours. I noticed that the original orings were not cylindrical on the in and out inside the posts. They were kinda squared off. I'm guessing that either its leaking there or the original o ring on the lid must have been thicker or maybe the poppets are leaking by. Anyone else with similar experience? I guess the next step is to try to use some leak detector and see if I can locate that slow leak. Is it normal for the lid to be that loose without pressure. It was holding pressure at the LHBS with its original orings.