Replacing air scoop

Hi, I recently put in a new expansion tank but since the change there has been a steady leak that seems to be coming from between the air scoop and tank. I only used thread tape, so i'm going to try block sealant to see if this resolves the issue. I'm not sure if it will because I may have discovered a hairline fracture in the air scoop female connection.

If the block sealant around the expansion tank does not solve the problem, I was curious how difficult it is to replace the air scoop. While this isn't a great view (something i have handy on my phone) it shows the the layout, air scoop, and tank. It appears there are threads on each side of the air scoop. Is it as simple as unscrewing the air scoop and replacing or is there some cutting and soldering needed here? If a better picture is required I can post one tonight.

Thanks in advance for your assistance.

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?

You have to depressurize and turn off any fill valve, but once you do that, you should be able to unscrew the thing and replace with a new one. Turn the boiler off first, and when done, repressurize the system and check for new leaks.

This is what I thought and is simple enough but the guy from HD said I would have to cut the copper to get to it even though I said it was all steel threaded around it. I was skeptical of the advice but added to my uncertainty. Thanks for the instruction and confirmation. I'm sure i'll be back if I experience any difficulties.

You will have to disconnect the copper before you can remove the air scoop. I think that jadnashua was thinking you talking about the air vent.

John