[meistersmudge]

Bought some used kegs and a keggerator awhile ago and am finally getting around to kegging a beer. I noticed that the keggerator has grey disconnects for the liquid as well as the gas. Should I replace the liquid with a black disconnect? I have an extra laying around. Is there any difference between the two or are they just different colors? I also wanted to know if any of you have any suggestions for checking for gas leaks without disassembling the keggerator.

[liquidbrewing]

You will probably have to replace the post on the keg if you want to change it back to the original gray/gas, black/liquid configuration.  The posts are different, I mistakenly put the black on the gray side on my first kegged batch, ended up with beer in the regulator!!  Not to mention it was a PIA to get off.

I would replace the posts back to the original if I were you.

As far as the leaks, make sure you use teflon tape on anything that doesn't have a gasket.  Hook everything up the way you want it.  Open the gas and any manifolds or distributors.  Big leaks should be very noticeable, a spray bottle of diluted Star San works great for me, because it foams up so much you should be able to find small leaks.  Spray everything down good.  Don't bother with the "Leak Detecting" sprays, use sanitizer.

Enjoy kegging, it will save you time and let you carb your beer faster.  I only wish I had done it sooner.

[oscarvan]

I think he bought the kegs separately from the fridge, in which case the posts are probably correct. Just to check, the base of the post is hexagonal on the liquid side, and cerrated on the gas side.

And yes there is a difference and no, you don't want to put a grey connecter on a liquid post. Check the kegs and at least put the right connector on the right post, but preferably have the right post in the right place, and the right connector on it.

[meistersmudge]

I purchased the kegs with the keggerator. The black disconnect I have doesn't seem to fit on the liquid post.

[corkybstewart]

Just to check, the base of the post is hexagonal on the liquid side, and cerrated on the gas side

Not always,  I have 2 kegs that are hex on both posts.  That's one of the reasons I prefer my pinlock kegs.

[euge]

Make sure you have the right posts for the QD's. Ultimately it doesn't really matter which connects are on there as long as they fit their posts properly. AND, you need to make sure you know which one is the "in" and "out" so you don't connect your gas to the liquid side as mentioned before.

Sounds like the previous owner went that route. Replace what he did if you want.

Now sometimes they get a bit sticky and the QD's won't snap onto their posts. A solution is to rinse the connect with hot water and wipe off the post, then coat it lightly (lightly!) with vegetable oil or keg lube.

[jeffy]

Tom Schmidlin posted some pictures of gas and liquid posts in this thread:
http://www.homebrewersassociation.org/forum/index.php?topic=3791.0
At the time I didn't know the difference, so this helped me a lot.
I really prefer the pin-lock kegs myself, but I have several of each.

[meistersmudge]

There is a liquid and a gas post on each of the kegs. The grey QDs lock on to both posts easily. The black QD doesn't lock on to any of the posts. If the grey are locked on and the gas is going to the "IN" and the liquid hooked to the "OUT" do I have anything that I need to worry about?

[jeffy]

There is a liquid and a gas post on each of the kegs. The grey QDs lock on to both posts easily. The black QD doesn't lock on to any of the posts. If the grey are locked on and the gas is going to the "IN" and the liquid hooked to the "OUT" do I have anything that I need to worry about?

No, no worries unless it leaks. 
But I'm not sure why your black QD doesn't fit.