Vacuum pump failed (at taxi in)

[Sean S]

Sheared the shaft on the vacuum pump on my 75F the other day. The shaft sheared with a clean break. I cannot believe the old only lasted 2071 hours...

[1967 427]

Sorry to hear the bad news about your bird.  My wife and I met last year at Oshkosh, hope to see you there again this year.

[Aerodon]

Yeah, just can't get good quality anymore.  Next time get the 215 series with cooling fins and then maybe you will get a mere 3000 hours.  Or add a cooling shroud and then 4000 hours?

 

Aerodon

[N201MKTurbo]

Seems like the best time to lose it!

[0TreeLemur]

Hey, tell us how you noticed.  Was there noise, vibration, or just instrument misbehavior?   Just curious what signs you had, especially while taxiing.

Thanks!

[David Lloyd]

In the Bonanza I lost 10 pumps over 24 years.  No vibration, no noise, nothing.  Just the vacuum needle laying over to 0.  Only one did something different, would only get a couple inches vacuum.  Next startup it worked fine.  Next leg it died in flight.  A couple failures were noticed at startup, one while shutting down, the remainder were in flight.  A couple less than 100 hours, most 5-600 hours, one went 1100 or so.  The last failure, I was on the ILS at Little Rock in low weather.  Wife saw the vacuum indicator needle flicker a time or two, go to 0.  She tore part of the cover from an approach plate book and handed it to me to cover up the attitude indicator.  Good woman.  I've watched the attitude indicators run down after a vacuum failure.  They will bob up and down, show banks. You got to catch it within a minute and cover up the indicator.  Even after the AI quits moving it is impossible to ignore, cover it up.  The Mooney I have now has a low vacuum light, a small gauge and an alternate vacuum source.  If Dynon every gets their ducks in a row, I will have a new panel with no vacuum pump required.

[0TreeLemur]

@David Lloyd thanks for that.   With a new IR, I was curious if there are noticeable symptoms.   I agree that your wife was really on the ball with that one. 

I installed the Aerovonics AV-20 timer, which includes a lot of lagniappe, one bit of which is a MEMS based attitude indicator that serves as a backup to the vacuum AH, and as a 30-minute battery.  An expensive timer, but cool to have in case of a vaccum failure.  In my experience it agrees with the analog AH quite well.

[Sean S]

1 hour ago, Fred₂O said:

Hey, tell us how you noticed.  Was there noise, vibration, or just instrument misbehavior?   Just curious what signs you had, especially while taxiing.

Thanks!

Red vacuum light started flashing and the horizon was listing to the left on a level tarmac!

[Hank]

1 hour ago, Bayern Speed said:

Red vacuum light started flashing and the horizon was listing to the left on a level tarmac!

That's how my failure on taxi out manifested. Plus the gage read "0." The whole 25 minute flight home it was bouncing around at a consistent ~170° left bank but varying climb / descent angles. Beautiful but turbulent VFR breakfast run that morning. 

[jamesm]

I have a pre-owned/slightly used (350 hrs ish) tempest Vacuum Tornado  pump aa3215cc that I would happy to part with 1/2 spruce sells for or reasonable  offer. That came off my C model earlier this year. The last couple years served as a step re tractor. Thanks to tankerair  and electric  step mod and  the wing leveler turn coordinator failed several years ago (right after ADS-B install, guess where my $500 ADS-B rebate went too ) no need for vacuum pump. plus save weight to boot.

 James '67C

[carusoam]

+1 Rob @takair for the electric version of the vac step...

I haven’t had a vac pump fail yet...

Best regards,

-a-