BrettKS Posted August 27, 2019 Report Posted August 27, 2019 Flying today and HI started spinning, attitude indicator rotated, vacuum reads zero. Landed uneventfully, but now for the repair: Is the vacuum pump the most likely item that failed? Could anything else cause this or should I go ahead and order the vacuum pump to expedite the repair? Recommendations on which pump to use? I'm going to take the cowl off and look at what's currently installed, but wondering what kind of options I'll have. No, not ready to go sans pump right now, but recognize that's the best way to go. Quote
jaylw314 Posted August 27, 2019 Report Posted August 27, 2019 It would be good to check your vacuum hoses first. After some panel work, I found my vacuum was zero. The shop checked, and the hose had come off at the firewall fitting. It did not have a hose clamp and must have been knocked off during the panel work. They reconnected it with a hose clamp and all was well... Quote
N201MKTurbo Posted August 27, 2019 Report Posted August 27, 2019 (edited) Most of the pumps let you see the coupler. take off the cowl and move the propeller while looking at the back half of the coupler. If it doesn't move, you need a new pump. BTW, you need a new pump! Edited August 27, 2019 by N201MKTurbo Quote
carusoam Posted August 27, 2019 Report Posted August 27, 2019 Don’t look in the logs yet.... How many hours did it have on it? OK, you can look now... Some die from infant mortality, for several reasons... Others get past 500 hours before wearing blades... worn blades stick and snap off... ending the vacuum portion of the pump... Some people OH them... realistically they are in the replace early and often category... others replace them with wet pumps that last extremely long... Many toss them at 500hrs to keep things from going awry in IMC... I’m guessing, you don’t fly in IMC? Best regards, -a- Quote
BDPetersen Posted August 27, 2019 Report Posted August 27, 2019 Sometimes strange things happen. My friend with an “F” model had a vacuum failure on start up recently. Scrutiny revealed a looseness in the elbow fitting in the top of the pump. The pump had been operating normally for hundreds of hours, but suddenly this became an issue. Engine mount interfered with tightening without first removing the pump, but that corrected the problem. Quote
65eTurbo Posted August 27, 2019 Report Posted August 27, 2019 Also, be concerned for your vacuum instruments after a vacuum pump failure. When the vacuum suddenly fails karma the carbon dust from the vacuum pump blades camp suddenly flow back into the instruments. Good practice is to place a filter in between the vacuum pump and the vacuum instruments. There used to be a company called it clear view filter that made filters that were clear so you could see how much damage had been prevented by having the filter inline. The clear filters are no longer available but I'd still consider an installation of A filter. My vacuum pump recently failed at my mechanic said "that filter sure saved you a lot of grief " . Quote
BrettKS Posted August 27, 2019 Author Report Posted August 27, 2019 Cowl is off. Could someone assist in identifying where the vacuum pump is? Quote
BrettKS Posted August 27, 2019 Author Report Posted August 27, 2019 1 minute ago, BrettKS said: Cowl is off. Could someone assist in identifying where the vacuum pump is? Actually, looks like it's right on top of the air filter. I don't see anything obviously disconnected. Quote
Greg Ellis Posted August 27, 2019 Report Posted August 27, 2019 34 minutes ago, BrettKS said: Actually, looks like it's right on top of the air filter. I don't see anything obviously disconnected. I think you may mean oil filter, not air filter? Quote
Greg Ellis Posted August 27, 2019 Report Posted August 27, 2019 41 minutes ago, BrettKS said: Cowl is off. Could someone assist in identifying where the vacuum pump is? 2 Quote
BrettKS Posted August 27, 2019 Author Report Posted August 27, 2019 11 minutes ago, Greg Ellis said: I think you may mean oil filter, not air filter? Yes, that's what I meant Quote
Bryan Posted August 27, 2019 Report Posted August 27, 2019 I would be money that your vacuum (circled) has failed. Your local A&P will have extensive knowledge in finding/replacing and appears to be easy to get to. Past the pump, inside the cabin (generally), there is a suction regulator that can dial the exact pressure. The fact that your vacuum gauge is zero, I would bet money this is the source of your problem. Quote
KB4 Posted August 27, 2019 Report Posted August 27, 2019 Consider G5 or similar EFIS. Then whole system is removed. You may IRAN the system only to find your 30 year old AI and HSI need overhaul. Hopefully not, but my HSI quit. Replaced with G5. Hopefully just a missing clamp. Quote
BrettKS Posted August 27, 2019 Author Report Posted August 27, 2019 I'm glad I took the cowl off. Fresh out of annual and noticed that this ? exhaust piping was completely loose and easy to pull off. I imagine this could have been an issue in flight. Quote
47U Posted August 27, 2019 Report Posted August 27, 2019 As is MooneySpace tradition, posting wide-angle shots of a target-rich environment invites (what is hoped to) be "constructive commentary." Is your A&P/IA mad at you for some reason? There's a lot of "stuff" going on in there. (Sorry, not constructive.) Find a screw and nut to plug up that open hole in the firewall. Just inboard (above, in the picture) of the terminal block. Good luck! tom 1 Quote
carusoam Posted August 27, 2019 Report Posted August 27, 2019 Use some additional words to describe things... Loose exhaust piping after annual.... pretty much describes the thing that delivers flaming hot exhaust to the muffler... Is that what you mean? That would be really bad! As in do not fly until fixed... Or did you mean the big heater hose? This coming loose probably not a big deal...? Circled in the pic below? Unfortunately, I don’t see an exhaust piping in the pic... PP thoughts only, not a mechanic... Best regards, -a- 2 Quote
jaylw314 Posted August 27, 2019 Report Posted August 27, 2019 5 minutes ago, carusoam said: Use some additional words to describe things... Loose exhaust piping after annual.... pretty much describes the thing that delivers flaming hot exhaust to the muffler... Is that what you mean? That was kind of my reaction when I read that 1 Quote
BrettKS Posted August 27, 2019 Author Report Posted August 27, 2019 (edited) 11 minutes ago, carusoam said: Use some additional words to describe things... Loose exhaust piping after annual.... pretty much describes the thing that delivers flaming hot exhaust to the muffler... Is that what you mean? That would be really bad! As in do not fly until fixed... Or did you mean the big heater hose? This coming loose probably not a big deal...? Circled in the pic below? Unfortunately, I don’t see an exhaust piping in the pic... PP thoughts only, not a mechanic... Best regards, -a- Yes, that is the piping that I was referring to. My '?' before "exhaust piping" was meant that I wasn't sure what this piping was for. Still developing my aviation vocabulary and knowledge-base. Either way, it seems like this could allow exhaust fumes/carbon monoxide into the cabin. Correct me if I'm wrong.. Photo was taken after I reattached it and secured the clamp. I'll have a mechanic inspect it when he's working on the vacuum before I take it in the air again. Edited August 27, 2019 by BrettKS Quote
carusoam Posted August 27, 2019 Report Posted August 27, 2019 Have less fear.... 1) But get to know where exhaust can enter that piece of hose... it comes from upstream... 2) If the exhaust is leaking out of an exhaust tube, and that hose was missing, and you had the slide gate open to get air/heat into the cabin... see the slide gate control wire? The bigger problem is hot gasses being released under the cowl.... a large fire risk... 3) A broken heat muff allows exhaust into the heat system... using the heat allows the errant exhaust into the cabin... 4) The heat muff surrounds the muffler... and hides the broken parts... 5) Got a CO monitor? Now is the day to order one... Best regards, -a- 1 Quote
3914N Posted August 27, 2019 Report Posted August 27, 2019 +1 for CO monitor. A lot of added safety for 0.1 AMU. A digital monitor with PPM readout will give you a “health check” of your exhaust baffling before it becomes a safety issue. 1 Quote
Guest Posted August 27, 2019 Report Posted August 27, 2019 8 hours ago, BrettKS said: I'm glad I took the cowl off. Fresh out of annual and noticed that this ? exhaust piping was completely loose and easy to pull off. I imagine this could have been an issue in flight. That’s called “Scat” ducting, it delivers hot air from the muffler shroud to the cabin via the shut off valve. Your engine compartment wiring could use some attention and tidy up. Clarence Quote
MBDiagMan Posted August 28, 2019 Report Posted August 28, 2019 From now on I will be replacing the pump on a preventive maintenance basis. About four weeks ago I headed over the top on a 250nm flight. About 150 nm or so was over solid overcast with a METAR and forecast of VFR at my destination. I got about halfway across above the overcast and saw the AI turning severely. I looked at the horizon and I was wings level. I looked at the suction gauge and it was on zero. It wasn’t serious because I was confident that I had VFR ahead and I had about five hours of fuel on board. That said I still felt uneasy. If I would have had to go through the overcast it would have been less than ideal without my vacuum driven instruments. It got MY attention!, 1 Quote
jaylw314 Posted August 28, 2019 Report Posted August 28, 2019 1 hour ago, M20Doc said: That’s called “Scat” ducting, it delivers hot air from the muffler shroud to the cabin via the shut off valve. Your engine compartment wiring could use some attention and tidy up. Clarence Hey @M20Doc, what does "SCAT" actually stand for? It seems a rather unfortunate name more reminiscent of proctology... 1 Quote
Guest Posted August 28, 2019 Report Posted August 28, 2019 8 minutes ago, jaylw314 said: Hey @M20Doc, what does "SCAT" actually stand for? It seems a rather unfortunate name more reminiscent of proctology... I have to look it up, but it is a product of the Thermoid Co. Scat, Sceet, Cat and Ceet are common ducting solutions. Clarence Quote
N201MKTurbo Posted August 28, 2019 Report Posted August 28, 2019 31 minutes ago, jaylw314 said: Hey @M20Doc, what does "SCAT" actually stand for? It seems a rather unfortunate name more reminiscent of proctology... It is silicone CAT duct Quote
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