It runs from the throttle body elbow to the passenger side of the vehicle. The first picture is of it in the vehicle, throttle body elbow has already been removed. The second picture is of where it connects on the throttle body elbow and the third picture is of just the removed line.

 

Brake booster.

Don't ask me how it gets from the passenger side around to the driver side, it's routed somewhere in the bowels of the cowl, but that is what it is for.

 

Any idea what the part number is or what section it might be listed under in the JEPC? I'm looking for it but no luck so far...

It detaches pretty easily on the passenger side then it is just held in by a few plastic pieces. I broke it trying to disconnect it from the throttle body elbow... still not sure how to remove it there but I'll figure it out.

 

I slowed down to examine the vacuum line and can now see that the line itself did not break. There is a plastic L adapter that connects it to the throttle body elbow that broke. I believe I can remove the piece stuck inside the line I just need the attachments to reconnect it to the throttle body elbow.

 

The part # you may need is C2S15816. After looking at your hose , it is different from my 2002 XKR. If it pushes in and locks with an o-ring the part I listed may be correct. It is not listed anywhere in the XKR parts manual that I could find. After about thirty minutes at the dealer , the good folks at Hennessy Jaguar found it was used on S-types. It comes with the brass insert that you most likely will not use. I tried all kinds of ways to seal this hose but after a proper repair I finally got a P1111 code. It is the first time I have seen that code since I've owner both an XJR and an XkR.