Hello, all, and thank you for allowing me to join.
I am doing a head-gasket replacement on my 2000 XK8 convertible (original 4.0L engine) and am being very careful undoing the various plastic connections during engine disassembly. Things have gone well but slowly, and I'm now stuck at the last stage of puling off the inlet manifold before removing the bolts. I've encountered a narrow hard plastic tube inserted into the elbow below the throttle body and can't figure out how to remove it (I've already taken off the throttle body). The tube runs off the right side of the elbow and disappears into the right (passenger side, US) wheel arch, covered in heat shield fabric. There is no visible connection release I can discover - does this thing just pull out, or is there one of those typical Masonic-handshake connection releases and I just can't see it?
Appreciate any advice you can give me on this.

 

That's a vacuum line. I haven't removed mine recently but I think I read that you push the outer ring in and then pull the tube.

 

Kinda like the Chinese finger trap we played with as kids in the 50s/60s.

 

Folks,
Thanks to your insights, I was able to visualize the internal workings. The vacuum line is now free - I used a 3/8" quick-connect plastic release tool and it slid right out. Thanks to you both for getting this job back on track. Next, off with the 10 (+2) bolts and off with the inlet manifold.