Just had my second Sigma-Tek piston vacuum pump fail at 50-55 hours. After my swell Aero-advantage dual rotor pump was AD'd and killed due to multiple failures and the builder went Chapter whatever, I wanted the latest greatest thing, so I had the mechanic install the Sigma-Tek piston -- 5 yr/2000 hour full lifetime guarantee (not pro-rated.) First one failed at 50 hours. They sent a new one immediately, without waiting for a return, and offerered to cover some "R&I." I was on the other side of the state, and when I picked up the plane on a Sunday, there was no one there so they said they'd mail me the paperwork. Turns out they forgot, and so did I. Like a dummy, I then forgot to send Sigma-Tek the R&I.
The second one just failed after 55 hours. Spoke with their service & warranty mgr. today and he was very unhappy to hear that I had had a second failure, and said they'd ship me a new one in the AM first thing. He was quite concerned if I was "down" and away from home. Luckilly, no. He said send him the R&I bil,l and I mentioned the previous bill I had not sent and he said, "send it!" So at least they are being responsive.
He said my first was an "A" edition pump, and the one he sends me will be the "C" edition. He says that in previous editions, there may have been a slightly higher failure rate in the IO-540 (hard to say when the statistical pool is so small, which is a fair statement,) and interestingly, that is the engine that killed the Aero-advantage system, although I had 200+ hours on mine when I ripped it out, perfectly good. But it seemed therre were some harmonics problems with that set-up.
So ... If I had an IO-540 and were replacing a pump, I think I'd go with the old-fashioned one for now. I do have the Sporty's electic backup AI, however, and 2 GPS and AnyWhere map for finding my way, so I am not overyly concerned, and am going to give the piston one more more try.
I am almost positive one other 114 driver reported a Sigma-Tek piston vacuum pump failure. Who was that, and any others out there?
p.s. I have audio-through-headset warnings for vacuum, voltage, stall and gear ... my co-pilot was very amazed to hear the audio-nag-babe saying, "check Gyro! Check Gyro!" That could be a life-saver. this was solid VFR, but many have followed a by AI right into the ground.
Scott Sedam
N4843W, '77 114
Willow Run (YIP)
SE Michigan