I finally got around to servicing the clogged PCV system on my wife's 2005 S80, 2.5T, 155,000 miles. It appears the main culprit for the neutral or slightly positive crankcase pressure is the short length of hard plastic tubing (shown in red in the image below) that runs from a banjo fitting on the bottom of the intake manifold to a point where it T's into the larger diameter hose (yellow) just above where the large hose exits the top of the breather box. It was plugged up solid to the point that I couldn't even clean it out with a piece of wire. Because it is sort of "S" shaped, I tried to straighten it slightly in order to run the wire through it. Well, let's just say it wasn't very flexible. ("Snap!") The problem is that Volvo only sells the entire assembly of hoses bundled together in a common conduit. Price = $160 - $200 depending where you buy it. But then you also have to get down behind the engine to disconnect the other ends of the hoses. BTW, the smaller diameter yellow tube is a water line.

My question is, does anyone see anything wrong with simply the replacing the clogged/broken length of hose with some regular vacuum hose? The bajo fitting has a barbed nipple as does the other end where it T's into the larger hose. I found a piece of vacuum hose that fits those barbed nipples nice and snug. I can blow air through the large diameter hose, so I'm convinced that it's path down to where it ties into the turbo intake hose is obstruction-free.

So what's the consensus - replace the entire mess, or just the short length of small diameter tube?