Volvo 850 Turbo Vacuum hose question..
 

I have a volvo 850 turbo that has recently had some issues with the rpms dropping after acceleration at higher speeds. After looking around i noticed that my mechanic broke my vacuum tree the last time he cleaned out my PCV. The hose that has the broken piece in it is yellow and looks like it leads to the cabin. I need help identifying what the hose is called and what its used for so that I know weather or not this is the reason for my RPM loss.

Photo Album - Imgur

There are the pics of my Vacuum tree. I just need to know what that yellow hose it.

Thanks guys!

Does your boost gauge work ??

From what I remember, yes. Although, I've read that the hose i'm looking at is most likely the turbo gauge hose, which is a bit concerning since it wouldn't really explain why my car has the rpm loss at higher speeds like I listed. Ugh, back to researching...

Why don't you plug the broken stem with RTV and attach the hose to an unbroken stem on the tree?

Ah, the turbo gauge no longer works. Bingo. It's the turbo guage hose leading to the cabin. Also, since my mechanic not only broke it and failed to do what you recommended above, but also tried to conceal the fact that he did it, I'm for sure getting him to give me a new vacuum tree. The mechanic who did my last job was sloppy as hell, and for that he's going to have to pay.

BTW thanks for pointing me in the right direction with the Turbo hose comment you made above! :)