In a previous article, "John R. Copeland" said:
Dry vacuum pumps normally fail catastrophically by shattering their
graphite vanes. Personally, I've never detected warning signs other than
gradually accumulating carbon dust around the pump outlets.
When I see that, I schedule pump replacement without waiting for failure.

Jon's doing right by getting the whole vacuum system checked.
He could have a clogged filter, a small leak, or even a bad gyro bearing.

We had an AI once that was very slow to erect. First the mechanic
increased the suction to try and spin the gyros faster, but when that
didn't help we ended up replacing the AI.


--
Paul Tomblin http://xcski.com/blogs/pt/
I treat shops as military objectives to be penetrated and stripped of needed
resources in as little time as possible. She has adventures in them.
-- Joe Thompson