Leaking coolant

I just put a 6.6 diesel motor in a 2003 2500HD and as I was putting the coolant in I spotted a leak what sounds like the same area, the water pump is located just under and behind the power steering pump and there are two tubes coming off of the pump. I found my leak in a gasket on the back of the pump connecting a tube that runs to the back of the motor, there is an "O" ring for a seal on the top tube. But don't rule out the fact that it could also be the water pump itself sometimes they only leak when it's running and sometimes it will only leak when it's not running because there is an inner and outer seal and it will leak out of a vent usually at the bottom of the pump just behind the pull. You will have to get a closer look the best way would be to pull down the plastic skid plate under the front of the truck and you can see right up in there. I hope this helps!

I had a rotten hose (3/8" I believe) under the intake on left side and I thought I had a bad head gasket. Now I have another leak somewhere:(