Originally Posted by Diseasel300

The breather puck is not serviceable in the 603 valve cover. If it fails, it's just open to the valve cover and can lead to high oil consumption, you'll see it as a big puddle in the intake snorkel.

The good news is that the rubber grommet and breather puck from a VW TDI fit the breather port in the 603 valve cover like a glove and are super cheap parts. I've run one on my SDL for over a year and it dramatically cut oil consumption and virtually stopped all oil vapor getting to the intake snorkel.