A few things, apologize if this was posted in the wrong forum... maybe it should have done under the Boiler section?
Next, I put plenty of sealant on the expansion tank and put a little on the spot where i thought the hairline fracture was. It's confirmed, there is a fracture in the air scoop causing the leak. Since Monday we had a brand new water heater installed and spent a small fortune (new home owner), I temporarily patched the pinhole in the air scoop until i can fix it properly or stomach another service call if need be. Since this is a DIY forum, I'd really like to attempt the fix myself.
Here's a close up of the air scoop and piping around it. The steel piping is all threaded, can I just unscrew the air scoop or am I cutting it at the copper pipe to replace a new air scoop?