"G.R. Patterson III" wrote in message
...

snip
You can't expect the 100 hour to catch a bad vacuum pump - it's not on the
list
of items to inspect, but the ignition system is. My plane came out of
annual with
....."

Checking the vacuum pump actually is on my copy of the Annual/100 hour list
from the Cessna Service Manual for the 152. I don't have a copy of the 172
manual handy, but I suspect it is much the same. I usually do it during the
Annual/100 hour as I do a static RPM check and/or a runup to warm the oil
for an oil/filter change. (oil/filter change is not part of annual/100 hour,
but quite often done at the same time).

Just my $.02

John Severyn
C-152 N24495