The worst thing about a vacuum failure is not knowing it!!!
My suggestion is to put in a idiot light indicating that there is a
vacuum failure. It's an easy arrangement with a vacuum switch and a bulb.
When the light is on, go into partial panel mode.

My next suggestion is to put in a wet vacuum pump. The life spans on
these are usually in the thousands of hours not the 500 hrs as in the
dry pumps.

The next thing I'll hear is that my "belly has a little oil on it", "I
don't want to get a wet pump".

When it really gets down to it, whats more important, a clean belly or a
working vacuum system?

It doesn't get much more simple than that.





Nathan Young wrote:
Your AI and TC are vacuum powered? What kind of autopilot? Most the
Cherokees came with electric powered TCs/autopilots.

-Nathan


On Fri, 17 Sep 2004 05:17:36 GMT, Chuck wrote:


Hi group,

Seems to be a lot of experience out on this list, so I thought I might
ask a question.

I have a Cherokee 180 that is IFR cert, but both A.I. and Turn
Coordinator are vacuum driven. With both driven by vacuum, a pump or
engine failure in IMC will leave you guessing if you're right side up,
turning, or pitching.

I've considered replacing the A.I. or Turn Coordinator with an
electric driven instrument. But either would be expensive and
replacing the Turn Coordinator would break my autopilot. So, I've
decided the cheapest way to provide backup insurance is to put in a
back up vacuum pump.

Does anyone out there have any experience with the STC'ed backup
vacuum pump kits? Is one maker's kit better/easier to install that
others? And is there any information available on reliability? I'd
hate to put in a "backup" system only to have it fail to work!

Thanks guys.



Chuck
N7398W
San Antonio, Tx