Problems with Rapco dry vacuum pumps.

Just a warning for those who might consider purchasing Rapco dry vacuum
pumps. Make sure that your engine does not leak oil. If there is any
chance of an oil drip onto the Rapco vacuum pump it may eventually stop
working. The connecting shaft is vented to air. But if some oil drops
on the shaft it may get sucked into the pump and after the oil dries it
may seize the pump. I puchased a 216CW new pump from Spruce and after
20 hours of use it does not work. After returning it to Rapco they said
it was "oil contamination" and not eligible for warranty service, but
offered to replace it at a discount. They really ought to have a better
seal there to prevent the problem.

If you were really smart you would have ditched your pump and installed
the Aeon pump instead. More expensive than the normal dry pump but the
next best thing to a wet pump.



abripl wrote:
Just a warning for those who might consider purchasing Rapco dry vacuum
pumps. Make sure that your engine does not leak oil. If there is any
chance of an oil drip onto the Rapco vacuum pump it may eventually stop
working. The connecting shaft is vented to air. But if some oil drops
on the shaft it may get sucked into the pump and after the oil dries it
may seize the pump. I puchased a 216CW new pump from Spruce and after
20 hours of use it does not work. After returning it to Rapco they said
it was "oil contamination" and not eligible for warranty service, but
offered to replace it at a discount. They really ought to have a better
seal there to prevent the problem.

...you would have ... installed the Aeon pump instead
Actually I removed the vac pump and went to all electric - saved some
weight. But I do think that Rapco or any mfg should prevent something
like that with a seal.

Did you check the Aen pump for oil drip problems? Do they warranty
against oil entry?

Rapco can't put any serious seal on that pump that would last any
time because it's a dry pump, and seals need some lube. Rapco does have
a pump to fit the under-nose mountings like the O-200, where oil tends
to get into the pump, and that pump has a flinger and a drain port to
keep oil out.
Washing the engine with solvent can also wreck the pump. It
needs to be covered during spraydown.
We use Rapco pumps exclusively on five airplanes, and have no
trouble at all reaching 1000 hours.
Basically, your oil leak need fixing. Oil leaks represent an
attraction for dirt, which does no engine any good, and they're a fire
hazard. And some oil leaks are warnings to fix something before it
blows off completely and all the oil is lost overboard in flight.

Dan

Rapco can't put any serious "seal" on that pump...
... [They have a]... pump has a "flinger and a drain port" to keep oil out...
I don't care what its called - it should be on there. Is the
manufacturing cost of such feature so significant? I don't recall any
warnings that came with my new Rapco pump about simple oil drip hazards
or about a special pump model required. I only found out when warranty
service was denied.

...Basically, your oil leak need fixing.....
No kidding. But while you are trying to fix it or if you are unaware of
oil leaks you take a flight risk with the pump. Engines can START
leaking and ruin these "sensitive" pumps. A lot of homebuilders, like
me, have initial leaks until they are found and fixed - its not a lack
of trying.

This post is a warning to others about the risk they may take with such
pumps - unless they are 100% sure their engine does not leak and never
will leak. Even if they find/fix the leak quickly they will not know if
the pump is OK, since the pump tends to work for a while after oil gets
in there.

"abripl" wrote in message
oups.com...
Rapco can't put any serious "seal" on that pump...
... [They have a]... pump has a "flinger and a drain port" to keep oil
out...
I don't care what its called - it should be on there. Is the
manufacturing cost of such feature so significant? I don't recall any
warnings that came with my new Rapco pump about simple oil drip hazards
or about a special pump model required. I only found out when warranty
service was denied.

...Basically, your oil leak need fixing.....
No kidding. But while you are trying to fix it or if you are unaware of
oil leaks you take a flight risk with the pump. Engines can START
leaking and ruin these "sensitive" pumps. A lot of homebuilders, like
me, have initial leaks until they are found and fixed - its not a lack
of trying.

This post is a warning to others about the risk they may take with such
pumps - unless they are 100% sure their engine does not leak and never
will leak. Even if they find/fix the leak quickly they will not know if
the pump is OK, since the pump tends to work for a while after oil gets
in there.


Any good mechanic can find an oil leak its not that hard.

? Any good mechanic can find an oil leak its not that hard.

You miss the point. After you find it, it may already be too late
because the oil might have leaked on the pump. So anytime you discover
a (new) leak you cannot be sure that the pump was not contaminated. The
only sure way is to replace the pump. This is not necessary if Rapco
designed the pump to reject accidental oil spillage.

In article .com,
"abripl" wrote:
You miss the point. After you find it, it may already be too late
because the oil might have leaked on the pump. So anytime you discover
a (new) leak you cannot be sure that the pump was not contaminated. The
only sure way is to replace the pump. This is not necessary if Rapco
designed the pump to reject accidental oil spillage.

As far as I know, engines shouldn't leak oil in this location, so why
would Rapco or anyone else waste time designing a pump that is immune to
it? It seems that the solution would be to fix the real problem, the
oil leak, and simply replace the (relatively inexpensive) pump.

If you don't know how to fix the oil leak the first time, you may want
to consult with an experienced mechanic.


JKG

...engines shouldn't leak oil in this location...
What location? Did I mention a location?

why would Rapco ... waste time designing a pump that is immune to it
In fact if you read Dan's above post they do design pumps imune to the
problem.

And you still miss the point. You can develop an oil leak and not know
it for a while... Then you are at risk flying your bird....

It seems that the solution would be to fix the real problem, the
oil leak, and simply replace the (relatively inexpensive) pump....
Well at least now you concede the necessity of having to replace the
pump - irregardless of whether I do it or a mechanic.

If you don't know how to fix the oil leak the first time... etc...
My skill is not the issue here.... you don't know what it is, it could
be better than a certified mechanics.

My skill is not the issue here.... you don't know what it is, it could
be better than a certified mechanics.

You could have Googled and found this:

http://www.casa.gov.au/airworth/aac/PART-1/1-098.HTM

A government document that speaks of solvent and oil
contamination of Edo (now Sigma-Tech) and Airborne vacuum pumps.
Apparently Rapco doesn't have the only pump that can't keep out oil. As
I said, those dry pumps are limited in the sealing out of oil, since
the sort of oil seal needed needs oil to survive.

Another article:
http://www.seqair.com/skunkworks/Mai...acuumPump.html

Better fix that oil leak.


Dan