Which system fails the most?

[PTK]

I was wondering which system tends to fail more frequently: vacuum or electrical? 

My guess would be vacuum due to two components vs. one. i.e. pump and ADI vs. alternator. But I may be wrong. 

[MB65E]

I'm done with my vaccuum system on my 65E!

However, I've changed more alternators than vaccuum pumps. I think the mechanical ADI's fail more than either pump or alternators. I can't wait to upgrade my RCA ADI!! Wouldn't mind the RCA solid state unit, but for the price there is much more functions available with other units. 

-Matt

[PTK]

25 minutes ago, MB65E said:

I'm done with my vaccuum system on my 65E!

However, I've changed more alternators than vaccuum pumps. I think the mechanical ADI's fail more than either pump or alternators. I can't wait to upgrade my RCA ADI!! Wouldn't mind the RCA solid state unit, but for the price there is much more functions available with other units. 

-Matt

So failure rates from the field are:

ADI > alternator > vacuum pump

That’s intetesting!

I know what you mean about more functionality. This is why I’m thinking of putting in the new KI300 which provides output for my KFC150. Then if or when my vacuum fails and I decide to go further I can always relegate it to a backup role. Or simply remove the vacuum all together.

[Wayne Cease]

The pilot.



Sent from my SM-G950U using Tapatalk

[MB65E]

Seat to stick interface issues! Lol

:-)

-Matt

[MIm20c]

The electrical system has multiple points of failure as well. Older master relays, circuit breakers, wiring, alternator, etc could have problems.  I’m still not sure if I want to replace the current vac AI with a G5. A new vacuum pump was installed this summer so I might just run it until it sputters, last one went 800 hrs. 

[ArtVandelay]

The electrical system has multiple points of failure as well. Older master relays, circuit breakers, wiring, alternator, etc could have problems.  I’m still not sure if I want to replace the current vac AI with a G5. A new vacuum pump was installed this summer so I might just run it until it sputters, last one went 800 hrs. 

But they have battery backup, do you have vacuum backup?

[carusoam]

M20C...

My generator failed, the battery ran down, I became aware of the failure in VMC when the radio lights began to flicker in response to the already low voltage. Within 50 miles of being home...

I have not had a vacuum failure yet.

 

M20R...

Two vacuum pumps... two separate mechanical drive systems.

Two batteries...

Lots of warning lights regarding failures...

None have failed, yet...

Looking forward to going all Electric one day. In the far away future... with a second alternator for back-up... where the vac pump used to be...

Best regards,

-a-

[jlunseth]

The biggest problem is variable failure rate.  Here’s what I mean.  A dry vacuum pump might give you 600 hrs., or it might give you a little more or something less than that.  But if you replace it every 500 hrs., before it even thinks of failing, the chances of a failure are tiny.  Basically, it has a life of 500 hrs. and will fail some time after that if you just wait.  My experience with the alternator in my aircraft is that it has a variable failure rate.  It is not the alternator, but the coupler that fails (basically a clutch in the gear that drives the alternator).  For awhile there I was going through coupler every 100-200 hours, and in fact had a couple of them fail almost as soon as they were changed.  One was because of improper installation by the mechanic, the other just stopped working.  The one I have now is working better than any I have ever had, don’t ask me why, and it is closing in on 300 hours.  That’s a variable failure rate, and that is the biggest problem.  So I vote for the alternator.  I have had one vacuum failure, and no more after I started changing at 500 hrs.  I am on my fifth or sixth coupler (I honestly don’t remember) in the same period.  I have never had the instruments themselves simply fail out of the blue, there is usually some kind of sign of failure before hand.  Better get it into the shop.  

[carusoam]

Tremendous improvements for the generator crowd came when (the other) Gates built belts that last for an extra long number of revolutions...

Best regards,

-a-

[donkaye]

Knock on wood, the reliability of glass has been phenomenal.  My KI256 had to be overhauled every 1,000 hours or less and even after the overhaul would not show level when rolling out of a left turn from base to final.  While I never had a vacuum pump failure, I changed the main one every 500 hours.  The backup vacuum pump was electrically actuated and weighed a ton--in addition to being expensive.  Alternators on the Bravo seem to put out enough juice that they need to be overhauled only at TBO.

With the glass so far, I've needed to replace the fan on the G500; $50 plus 15 minute install time.  Garmin discovered they needed a more powerful one, so this one makes a lot of noise.

I have seen many G1000 displays that become dim after a few years.  Not good.  Still thumbs up for all glass.

[MIm20c]

7 hours ago, teejayevans said:

But they have battery backup, do you have vacuum backup?

In my case I have a aspen so the vacuum is my backup.  Both separate systems failing at the same time could happen but the likelihood is lower. 

[flight2000]

M20E over 7 years: Replaced voltage regulator 2x, alternator 1x.  Vacuum Pump was fine, no issues.

E33A over 18 months: Replaced voltage regulator 1x, fixed broken wires 2x.  Pressure pump still kicking along with no issues.

So, in my experience, something in the electrical system has failed more times than the vacuum side.

Brian

[ArtVandelay]

3 years for my J:
AI replaced
Vacuum pump replaced
Pamco electric vacuum backup failed
Alternator field wire, fixed by hangar fairies.

I removed Pamco, kept the vacuum AI for now until the G5s prove themselves reliable. Eventually I will get my 6lbs back.