I finally dug into my dash to find out where I was getting a vacuum leak from. Tuns out to be the vacuum switch itself. I was wondering if this widget is something that can be repaired or if I should buy a new one. I checked the FAQ section but didn't see anything addressing this. I suspect either the rubber valve part has shrunken and/or the plastic clip cracked and wasn't holding it all together properly. The clip broke as I was fiddling with it. I see I can drill a hole in the disc part of it and mend the switch back together with a couple zip ties or small machine screw and nut.

What would be a safe lubricant for the rubber part? Silicon was my first thought but I recall that the fumes are damaging to the oxygen sensor. I did see in the FAQ WD40. Would that work? Maybe a light coat of something like wheel bearing grease?

Thanks