"Jay Honeck" wrote
How IS it that the FAA allowed installation of the almost completely
unreliable "dry" vacuum pumps, after so many years of success with the
bullet-proof "wet" pumps?

You don't really imagine FAA certification procedures do anything to
improve safety, do you?

Experience seems to show that dry pumps are just
a catastrophic failure waiting to happen

Yeah, basically. They're junk. But they're a few ounces lighter, a
few bucks cheaper (though of course not on a per-hour basis), and they
leave an oil slick on the belly no matter what you do.

Michael