PMcClure Posted September 16, 2016 Report Share Posted September 16, 2016 I replaced my perfectly fine vacuum pump last annual with over 800 hours as part of preventative maintenance. Only to have it fail for no good reason a few months later. $638 part that should cost about $100. Plus the cost to remove, replace, remove and replace. I have had similar experiences with batteries, alternators, starters, fuel pumps etc... It chaps my hide that these parts cost 5-10 times what they should but then fail and could kill you. And in general, recovering warranty value is a major hassle. Pump was a SIGMATEK AIR PUMP 1U128-006. Rant over. Thank you. Quote Link to comment Share on other sites More sharing options...
Cruiser Posted September 16, 2016 Report Share Posted September 16, 2016 Infant mortality is primary failure your story goes a long way in validating "if it ain't broke don't fix it" 3 Quote Link to comment Share on other sites More sharing options...
RLCarter Posted September 16, 2016 Report Share Posted September 16, 2016 Go with a rebuilt Rapco, same warranty 2yr/1000hr at about a 1/3 the cost ($237.95)...just my $0.02 2 Quote Link to comment Share on other sites More sharing options...
PMcClure Posted September 16, 2016 Author Report Share Posted September 16, 2016 Thanks for the advice. I am generally in the "ain't broke don't fix it" camp. But general advise is to replace vacuum pumps at 500 if you fly IFR and depend on it. How many people subscribe to this theory. Or better to just let it fail whenever. Quote Link to comment Share on other sites More sharing options...
cnoe Posted September 16, 2016 Report Share Posted September 16, 2016 FWIW I'm using a Tempest vac pump with the vane wear indicator port that at least gives you some indication of health. I have no intention of randomly replacing it; I'm much more concerned with infant mortality. Instead I PLAN on its failure by utilizing an electric backup pump PLUS an electric standby attitude indicator. Then there's always Foreflight displaying the AHRS info from my Stratus. When (not if) my legacy vac pump craps out I have a few options to choose from. Sent from my iPad using Tapatalk 3 Quote Link to comment Share on other sites More sharing options...
Marcopolo Posted September 16, 2016 Report Share Posted September 16, 2016 PM, 20 hours is extreme infant mortality. Some pumps require a specific direction of rotation although I believe most Sigma-Teks are bi-directional. Sorry to hear about this failure, glad you were in a position to notice it and return safely from it. Ron 1 Quote Link to comment Share on other sites More sharing options...
jetdriven Posted September 16, 2016 Report Share Posted September 16, 2016 (edited) Was any Teflon tape or sealer used on the pipe threads for install? Any silicone spray used to slip the highs on fittings? Were all the lines blown out or checked for deterioration? Do you have a CV1J4 filter? Anything other than air gets in that pump and it can fail very quickly Edited September 16, 2016 by jetdriven Quote Link to comment Share on other sites More sharing options...
PMcClure Posted September 16, 2016 Author Report Share Posted September 16, 2016 21 minutes ago, cnoe said: FWIW I'm using a Tempest vac pump with the vane wear indicator port that at least gives you some indication of health. I have no intention of randomly replacing it; I'm much more concerned with infant mortality. Instead I PLAN on its failure by utilizing an electric backup pump PLUS an electric standby attitude indicator. Then there's always Foreflight displaying the AHRS info from my Stratus. When (not if) my legacy vac pump craps out I have a few options to choose from. Sent from my iPad using Tapatalk I'll check these points, thank you. I do know a new filter was installed and lines cleaned or replaced at annual. New filter ordered is a RAPCO RAB3-5-1. Interesting point on the Tempest, I'll look into that. Regarding failure modes I have experienced 3 pump failures, one in IMC, 2 in VFR. 1st one failed at 500 hours, 2nd one was infant mortality as was this 3rd one. Mind you I only have about 800 hours flying. My Ovation has a stand by pump and back up AI. The 1st failure was in an older Mooney with no back up pump or AI. That one was in VFR as was this last one, thank goodness. The failure in IMC was in my Bonanza which also had a history of erratic AP issues. It did not have a standby AI but did have a standby vacuum pump. I had fewer hours experience then. It took me a while to recognize diagnose and act. I don't want to do that in IMC again, but do practice partial panels more often as a result. Bottom line, it seems infant mortality is a bigger risk than flying around with an 800 hour pump. 1 Quote Link to comment Share on other sites More sharing options...
peevee Posted September 16, 2016 Report Share Posted September 16, 2016 27 minutes ago, PMcClure said: Bottom line, it seems infant mortality is a bigger risk than flying around with an 800 hour pump. Tough to say. Ours is at 600ish and at least based on anecdotal evidence I agree. Our A&P also seems to agree. Makes a good case for a Garmin or dynon digital doesn't it? 1 Quote Link to comment Share on other sites More sharing options...
Mooneymite Posted September 16, 2016 Report Share Posted September 16, 2016 I've always been a "wait until it fails" guy since the MTBF is so variable. However, like CNOE, I've installed a Tempest with the vane wear indicator. I suspect that when those vanes approach the limit, I'll replace the pump preemptively. I've been incredibly lucky. All four failures have been in clear weather, or on the ground....so, my time is coming. Quote Link to comment Share on other sites More sharing options...
PMcClure Posted September 16, 2016 Author Report Share Posted September 16, 2016 9 minutes ago, Mooneymite said: I've always been a "wait until it fails" guy since the MTBF is so variable. That is kind of the point of the original rant. For $600 you think a pump would be more reliable or at least predicable. Quote Link to comment Share on other sites More sharing options...
jetdriven Posted September 16, 2016 Report Share Posted September 16, 2016 1 hour ago, Mooneymite said: I've always been a "wait until it fails" guy since the MTBF is so variable. However, like CNOE, I've installed a Tempest with the vane wear indicator. I suspect that when those vanes approach the limit, I'll replace the pump preemptively. I've been incredibly lucky. All four failures have been in clear weather, or on the ground....so, my time is coming. Im a wait until it fails kinda guy, too, but a vacuum system failure in IMC is quite a hazardous situation, so I mitigated it with the vacuum warning light and a standby electric attitude. 2 Quote Link to comment Share on other sites More sharing options...
peevee Posted September 16, 2016 Report Share Posted September 16, 2016 Just now, jetdriven said: Im a wait until it fails kinda guy, too, but a vacuum system failure in IMC is quite a hazardous situation, so I mitigated it with the vacuum warning light and a standby electric attitude. you would think they could have a system that fires up the electric standby pump automatically when a low vac situation exists. Quote Link to comment Share on other sites More sharing options...
cnoe Posted September 16, 2016 Report Share Posted September 16, 2016 1 hour ago, Mooneymite said: I've always been a "wait until it fails" guy since the MTBF is so variable. However, like CNOE, I've installed a Tempest with the vane wear indicator. I suspect that when those vanes approach the limit, I'll replace the pump preemptively. I've been incredibly lucky. All four failures have been in clear weather, or on the ground....so, my time is coming. Im a wait until it fails kinda guy, too, but a vacuum system failure in IMC is quite a hazardous situation, so I mitigated it with the vacuum warning light and a standby electric attitude. I wish mine was tied into the JPI's warning light which jumps out at me much more than the stock annunciator. Instead I added a small vac gauge in the middle of my panel that at least gives me a shot at seeing the failure quickly. Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
Mooneymite Posted September 16, 2016 Report Share Posted September 16, 2016 36 minutes ago, jetdriven said: ...so I mitigated it with the vacuum warning light and a standby electric attitude. Yes, my C has a Hi and LO VAC light to help with recognition before the gyros tilt. I practice partial panel and in a Mooney, it's not too tough. Adding to the confusion of Vac loss is the fact that you also lose your PC. What a great help that is! However, loss of vacuum in IMC requires immediately notifying ATC and, in my opinion, declaring an emergency. Quote Link to comment Share on other sites More sharing options...
201er Posted September 16, 2016 Report Share Posted September 16, 2016 33 minutes ago, cnoe said: I wish mine was tied into the JPI's warning light which jumps out at me much more than the stock annunciator. Instead I added a small vac gauge in the middle of my panel that at least gives me a shot at seeing the failure quickly. Sent from my iPad using Tapatalk I like how well organized your pannel is with all the checklists, labels, and even speeds on the gear handle. Did you add those? Quote Link to comment Share on other sites More sharing options...
Oldguy Posted September 16, 2016 Report Share Posted September 16, 2016 4 hours ago, cnoe said: FWIW I'm using a Tempest vac pump with the vane wear indicator port that at least gives you some indication of health. I have no intention of randomly replacing it; I'm much more concerned with infant mortality. Instead I PLAN on its failure by utilizing an electric backup pump PLUS an electric standby attitude indicator. Then there's always Foreflight displaying the AHRS info from my Stratus. When (not if) my legacy vac pump craps out I have a few options to choose from. Sent from my iPad using Tapatalk Paul, I had Rickey put a Tempest on mine in 2014 and have not had any problem. But just in case, I am pretty much an exact copy of what cnoe has in his and test my standby every third flight or so. Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted September 16, 2016 Report Share Posted September 16, 2016 Did you disassemble the failed pump to see if you could tell what caused it to fail? Quote Link to comment Share on other sites More sharing options...
Mooneymite Posted September 16, 2016 Report Share Posted September 16, 2016 (edited) 19 minutes ago, N201MKTurbo said: Did you disassemble the failed pump to see if you could tell what caused it to fail? In all of mine, the drive shaft was sheared, but I suspect that was a result of worn vanes, not the cause. Edited September 16, 2016 by Mooneymite Quote Link to comment Share on other sites More sharing options...
cnoe Posted September 16, 2016 Report Share Posted September 16, 2016 52 minutes ago, Mooneymite said: In all of mine, the drive shaft was sheared, but I suspect that was a result of worn vanes, not the cause. Yeah those frangible drive couplings will let go pretty quickly if something impedes the vanes. That sure beats risking damage to something in the accessory case. About 18 months ago I moved some stuff around in the vac system and must have got a small contaminant in the stand-by pump side of the system. The moment I turned the switch on to test it the coupling immediately popped and the gauge was instantly at zero. "Maintenance Induced Failure", and my fault entirely. Damn! After that I have been super-careful anytime the vac system is opened up 'cause even an old hose can shed rubber internally just pushing the hoses onto their fittings. 1 hour ago, 201er said: I like how well organized your pannel is with all the checklists, labels, and even speeds on the gear handle. Did you add those? A few months ago I replaced all my interior placards with a set from Higher Graphics that they allowed me to customize as desired. I added the gear speeds along with several other tweaks. I also chose to place my rocker-switch (small) labels "under" the switches as opposed to on the switch-cover top. They also included new labels for the fuel pull-drain and selector which I sorely needed. 3 Quote Link to comment Share on other sites More sharing options...
PMcClure Posted September 16, 2016 Author Report Share Posted September 16, 2016 1 hour ago, N201MKTurbo said: Did you disassemble the failed pump to see if you could tell what caused it to fail? sheared Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted September 16, 2016 Report Share Posted September 16, 2016 (edited) 1 hour ago, PMcClure said: sheared Of course it sheared! The coupling shearing is not the failure, it is just the mechanism to keep it from destroying your engine when it fails. Did you disassemble the pump to see what made it lock up? Did it have Teflon tape residue in it? did it have oil in it? Any other foreign matter in there? Was there any unusual wear marks on the chamber? Were the vanes still in tact and the hub cracked? Edited September 16, 2016 by N201MKTurbo Quote Link to comment Share on other sites More sharing options...
Guest Posted September 16, 2016 Report Share Posted September 16, 2016 In my airplanes I put the small vacuum gauge and the warning light for the SVS beside the AH, making it instantly apparent when it fails. Clarence Quote Link to comment Share on other sites More sharing options...
cnoe Posted September 16, 2016 Report Share Posted September 16, 2016 I struggle with acronyms sometimes. "Synthetic Vision System"? Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
Guest Posted September 16, 2016 Report Share Posted September 16, 2016 40 minutes ago, cnoe said: I struggle with acronyms sometimes. "Synthetic Vision System"? Sent from my iPad using Tapatalk Standby Vacuum System it uses engine intake vacuum as an emergency source. Clarence Quote Link to comment Share on other sites More sharing options...
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