First engine drop

[vancouver86/911]

I'm in the middle of my first engine drop in my 1986 911 ROW Carrera cabriolet. I'm dropping the engine as I believe I have a broken clutch fork. I'm replacing the clutch while I'm at it too. I am attempting this with the aid of my Bentley manual, blind luck and copious quantities of Molson Canadian beers. The least of my worries is keeping the beers cold as I am doing this outside and I have frozen puddles in my driveway. I was going to wait until spring to do this but curiousity and bad judgement has gotten the best of me.
In the process of disconnecting all the wires and hoses I have run across a broken rubber hose. It is located right above the oil filter, just to the rear side of the oil filler tube. This hose connects to a circular metal disc with a hose fitting on top. The rubber is cracked right through on this hose near where it exits the inside of the engine bay wall. What is this hose for and what affect will this cracked rubber hose have?

[john walker's workshop]

vacuum leak. try some large heat shrink tubing over it, if there's room.

[mholbrook38]

Get a new one. Don't mess around with trying to save it or patch it. It is a formed hose I believe. The circular metal disk goes into the back of the intake bellows. Holes in this hose cause massive vacuum leaks.

[vancouver86/911]

This is a picture of the torn rubber hose, it is circled in white and the white line is where it is torn. What is this piece called so that I can order a new one?