>>>>>>>>>>>>>
Vacuum pumps are notoriously the weak link in the vauum/ gyro system.
The
bulk of the failures occur with less than 500 total hours on the vacuum
pump
and many occur within a few hours of installation of a new pump. (I've
done a
study of vacuum pump failures for a notable case)
<<<<<<<<<<<<<

Jeff,

For those of us with vacuum pumps (on my spamcan in this case), given
your experiences do you recommend changing the vac pump
"prophylactically", i.e. change it when it hits 500 hours or so (whether
working or not) as the recent SBs from the manufacturers recommend, or
do you recommend the "don't touch it if it hasn't broken yet"
philosophy? I have heard (not based on actual data) that they are likely
to either last 10 hours or 1000 hours.

Any insights to share?

-Jon C.