Volvo 745 B230F Regina.
I recently noticed that the larger of the two vacuum lines running from the top side of my throttle body to the vacuum canister was hardened and split open at the end where it presses over its TB fitting.
At first I thought it would fix an illusive manifold vacuum leak, but discovered that this line sees throttle vacuum. My first attempt to repair this hose was to cut off the cracked end and re-fit it to the TB, but it was too hard from 19 years of texas heat.
I am hoping this will explain the loss of air conditioning from my dash vents when going up hills, as the condition occurs when vacuum demand is high and throttle is open wider than usual (I have read about R&R of the ventilation vacuum motor and it sounds like a beating.)
While looking for a replacement, I removed the hose to show my indy parts guy. He was out of stock, and sent me across the street where they wanted 6 bucks a foot! no way! I just drive home with the hose removed. The car drove fine, or as good as it normally does. So now I'm wondering exactly what this hose does, and under what conditions. Is there a Volvo guy out there who actually knows?