Rapco Vacuum pump lifespan

With all the new options available, there's probably nobody still thinking about a vacuum system. But just in case, I thought I'd pass this along.

My new, warranteed for one year or 1000 hours Rapco vacuum pump failed at two years, 10 months and 205 hours. I used the complete kit that Spruce sells, which includes a model #215cc Rapco pump. Anybody else get more than 200 hours out of theirs?

There was absolutely no warning. It was working fine on the previous flight, then produced zero vacuum on the next. Good thing I never got around to going for the Instrument ticket, I guess. If it failed like that under actual IFR, I wonder if I would have noticed in time. In fact, I wonder how long it was dead on the previous flight.

I'm tempted to switch to something else, but at this point, it's just not worth it. A rebuilt pump is $186, which is a heck of a lot less than junking two servicable gyros (one only a year old) for a Dynon or something (yes, my yellow-tag'd DG failed last year). I noticed that Spruce sells a special cooling shroud for the pump, so I bought that, too. Maybe I'll make it to 300 hours next time.

I think we've got more than 200 on our rapco. It's been a good pump so far. Did you make sure all your lines were free of contaminents? Little pieces of just about anything will cause a pump to fail. On the other hand, trying out the Sigmatek Apex piston pump might be worth a shot.

I have 145

Thanks for the heads up! I have around 145hrs on mine with several hours of "actual". Believe me this is one thing will kill you two ways. First if it fails and second if you think it has failed. I was going to replace it at 500hrs but I will watch it even closer now that you have reported your experience. I doubt that one would have much of a chance after an inflight failure in actual IMC. Even with a known vacuum pump failure, a long flight on a dark night using a wet compass and a turn coordinator is a demanding experience. Got to respect those old Mail Pilots. It is a good reason to have a TruTrak Pictorial Pilot and Altrak.

Bob Axsom

Ours too

Hi John,

On the way back from Brenham a few weeks ago with you, Daryl, and Phil, ours crapped out too. It was fine coming in from Wharton, but the gyros never came alive after startup to come home. That was at 96 hours and I haven't had a chance to look at it since. I've got the old vacuum pump from the Archer the engine came off of so I might try swapping the two & make sure it's the pump first, but I'll probably be ordering a new one and adding a blast tube as well.

BTW, I've still got the pictures but can't find the USB cord for the camera. I'll get one this weekend and email the pictures.

My rapco has been working well for 800 hours. Knock on wood Another rv on the field changed out his pump (don't know which brand) at ~1200 hours just because he thought it was time. We pulled it apart and were convinced it would have gone to TBO with no problem.

Remember to change out the filter at regular intervals. When you install your new pump make sure you vacuum out all the hoses first. Sometimes when pumps fail they spit junk back into the hose. This junk is just waiting to trash your new pump or your gyros.

Z

My original Rapco pump failed at 6 hours. My replacement has about 95 hours and seems OK so far. I will definetely get the Sigmatec if this ones fails. I know the people at Rapco and they graciously replaced it for me so I didn't have to go thru Aircraft Spruce (where I bought it). I had used a teflon sealant on the fittings. They said that may have caused the failure. They recommend just putting the fittings in dry, and not overly tight. I guess that makes sense, since a minute leak would not be bad.

Roberta

Dry pumps

Dry vac pumps are a crap shoot. It's biggest enemy is dirt due to poor filtration, poor hoses, and oil. I had a new Sigma Tek die after 130hrs. while a rebuilt Rapco lasted more than 500hr.. Should the oil seal behind the drive seap, even just a tad, it will eventually make it's way internally in the pump. Rapco AKA OPrfer Hannifin, and also unidirectional, They don't like it when the engine is turned back wards to often. A good measurement of pump life is the gauge, not idiot lights. The gauge will respond to weaknesses of a dying pump, such as increased engine speed for proper vac, loow recovery from idel, lowere than normal vac when idling, and if it gets the "shakes" start looking for a replacement.
The new Sigma Tek piston pump is promissing, but a friend just installed of in his Piper. It failed in less than a month. It can happen and a replacement was installed. With most components in aviation, the new pump, for me, is a wait and see. Still the concept is good.
Beter solution is all electric.