The picture you showed is very similar to mine. I installed the air
scoop, as well as the auto-bleeder. But it seems like I installed my
Expansion tank in the other hole on the air scoop.
On the bottom of the air scoop is the expansion tank and the bleeder
is on the top. I'm not standing in front of it, but I think that's
the way it is. Works very good for me. I used to have one heck of a
time bleeding all the air out of my system, but with this setup, it's
done automatically...though it sometimes takes a week or two. My
pipes have never been quieter.
I'd replace the bleeder altogether, with one similar to what is
described here. They get full of mineral deposits pretty easy.