Leaking Keg question?

I put a batch in a keg last week to condition for a few days until I kicked one in rotation. Hit it with CO2 each night and was concerned with the amount it took each time. Did a starsan spray test today and found that it was leaking from the gas 'in' post, right in the middle. I kicked a keg today so the leaky one is now hooked up to the gas line and it doesn't appear to be leaking out. Question is - what do I need to replace in order to fix this one after the keg is empty?

You can replace the whole post, they are relatively inexpensive, but you need a special wrench so you don't jack the keg up permanently.

That being said, I have the same problem with 3 of my cornies. However, all I have to do is press the little valve down or at the very most push it over with my finger nail. There's usually a little beer residue that I use to check for bubbles, then wipe it clean. Never had a leaking problem.

If it's leaking from the poppet itself, (the thing that pokes up in the very center of the post), then no worries. It won't leak now that it's hooked up to a QD. If you want to fix it after it kicks, you can just buy a new poppet, as it's most likely that which is leaking.