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Life expectancy of Vacuum Pump

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philrenyer

I'm New Here
I am working on my annual and would like to know what the life span of a Rapco vacuum pump might be? I presently have 450 hours on the plane and there is some darkening of the exhaust hose. Any comments would be appreciated.
 
Vac

I have heard it could be as low as 500 hrs. Mine is at 530 right now so I will be looking at a replacement (Dynon) in the near future.
 
Inspect It

On newer models there is an inspection port so that you can see the remaining length of the vanes. If there is significant wear, I would replace it, that is:

1) If you strictly fly VFR, you can run it until it fails.

2) If you rely on it for IFR, consider replacing it now. That decision also depends on what you have as a backup.
 
make sure you have an inline filter between the pump and your instruments. far too many think the inlet filter is sufficient. a pump failure could also cause imminent failure of gyros and plugged orifices. the $6 or $700 pump replacement could cost a lot more!
 
Try a Tempest When You Replace

I think they are currently rated at about an 1100 hour TBO. They also are the ones with the inspection ports so you can see the vanes and replace on condition rather than guessing their status !!

We have one on a o-540 with a few hundred hours, very nice setup for an IFR machine.

Ed
 
i had the last one go to 1,300 hrs...........

with the wear indicator past the last 1/3 indication. it sheared off the plastic shaft. you need to make your own decision. i will probably replace at 800 hrs or so.
 
philrenyer said:
I am working on my annual and would like to know what the life span of a Rapco vacuum pump might be? I presently have 450 hours on the plane and there is some darkening of the exhaust hose. Any comments would be appreciated.
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It's been a few years since I've owned or flown consistently an airplane with a "dry" vacuum pump but sudden failure around 500 hours was typical.

If you are using the airplane IFR precise flight makes (or made at least) an inexpensive setup that tapped manifold vacuum for backup. You couldn't use full throttle and still have vacuum, but at reduced power it worked great.


IIRC you can get a rebuild kit for the rapco pumps.

FWIW the older wet pumps were messy but much more reliable. We have one in the "family fleet" that was installed new in 1963, and has been reinstalled after engine overhaul but otherwise continues to "just work" after 47 years.
 
I installed a rebuild kit (just the carbon parts IIRC) at around 500 hours, but the originals were hardly worn. I replaced the whole unit at 1000 hours preemptively. I did not take the 1000 hour/500 since rebuild pump apart to see what sort of wear was present.
 
Pump life

I see most brands of dry pumps fail between 500 and 600ish hours. The exception seems to be the New AA3215CC / AA3216CW
Tempest pumps which I have seen go to TBO on several aircraft. Good luck, Russ
 
they fail just after take-off, at night, in IMC but never during the day under VMC...ask me how I know.

No more vacuum pumps for me..I'm all electric :)
 
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