Leaking Valve Question

I just converted to kegging. I kegged two batches two weeks ago and added priming sugar to naturally carbonate. I just hooked up the ball lock connection to the picnic tap line. One of the kegs is leaking from in between the ball lock pin and the ball lock connector. I hooked the connector up to my other keg and does not leak. Since I am new I am not sure what other facts to include. Anyone have suggestions what this could be?

did you change the o-rings out before you filled the kegs?

:cheers:

Just typed a long response then a light bulb went off and I checked the keg. The o ring on the top of the pin is missing. Thanks.

easy fixes are always good.

:cheers: