I forgot, but recently, after I replaced my vacuum pump as a prophylactic, I
noticed my Attitude Indicator was "lazy" in becoming erected.  Lacking AI
Viagra, I called Lancair to buy a replacement (I don't like overhauls).  

Lucky me!  Lancair avionics has almost no requests for vacuum panels; there
were a few vacuum gyros approaching the end of their 3 month shelf life and I
could purchase one for slightly over their cost.  Sucking in my breath (about
2.5 inches worth), I ordered a new, lighted AI with the famous Lancair logo.  
Then, I got to thinking - how long had my original gyro sat on the shelf or
in the panel before it was ever used.  Remember, oils eventually dry/harden
and bearings don't like that!.

Keep this in mind - I only had about 400 hours on the original but it had a
few years "on the shelf."

Note to Bill Harrelson - I know you backed up the pump, in 12 years of
personal experience, I have had no pump failures, but 2 instrument failures.  
BTW, I also run a cooling shroud on the pump body.

Scott Krueger
N92EX

Electrons never get tired.  Use'm, abuse'm, but don't lose'm.