I had my brother pick up a used freezer from Craigslist. The ad said that it worked. My brother verified that "it worked," and I got it the day before I got all of my keezer components, so I took their word for it.
Two weeks later, I finished my keezer (about a $1700 project for 8x CO2 faucets + 2x Nitrogen faucets and all the goodies that went along with that). I moved all of my kegged beer from my existing refrigerator-turned-kegerator to my new keezer and plugged it up.
I checked the temp the next morning and it was at 65 degrees F. I double-check the wiring on everything and it's right. I can hear the compressor kicking on, and when I felt it with my hand it was getting warm just as it should, but the inside isn't getting very cold at all.
So I called up my brother, who has some experience with refrigerators/freezers/HVAC but is by no means an expert, and he checked the refrigerant. The valve stem that's used to fill it (I'm not sure what it's called -- it looks like a valve stem to me) sticks open when it's depressed, causing R12 to spray out (take that, ozone layer!). It's holding pressure when the valve stem is closed, but it appears to have leaked out.
After talking with a few friends and some HVAC folks, they've told me that it'd be pretty easy to cut that valve stem off and re-braze a new one on. Since the system is 9 years old per the mfg date on the compressor, I don't think that it has any other leaks aside from the valve stem. Only a flush and real nitrogen pressure test will tell, though. Luckily for me, I have some friends who do that sort of thing and love beer.
That being said, R12 is both expensive and very unfriendly to the environment so I'd rather not use it. Several folks have mentioned switching over to R134A or R290. Do any of you folks have any experience with this? Am I better off just biting the bullet and going with R12 since I don't have to worry about the oil in the system, or is it worth it to spend the extra time flushing out the system and switching over to R134A or R290? Is R290 dangerous to use in a freezer?