Newowner Posted July 30, 2019 Report Posted July 30, 2019 Hello Mooney owners. Just bought 1966 M20F. Was flying it few days ago for about an hour and after shutdown during push back notice fuel dripping from near nose wheel on the left side drain tube (small metal tube). Talked to few A/Ps and got different answers. Need your expertise if it’s normal or I need to worry about it. Thanks. Quote
carusoam Posted July 30, 2019 Report Posted July 30, 2019 Hey new owner... How long do you intend to be a new Owner? You can always change your screen name... but, then people will have a hard time recognizing or remembering you... While you are not so busy... look up in the search function... ‘sniffle valve’ Learn How that works and why... You just may have found an ordinary part of your IO360... Or you have a different challenge altogether... PP thoughts only, not a mechanic... Best regards, -a- Quote
Newowner Posted July 30, 2019 Author Report Posted July 30, 2019 :))). Thanks for a quick response. I’ll be new owner until I trust this airplane and feel comfortable with it. I searched that valve and someone mentioned that it rubber. My leak is from metal little tube and it was dripping about 1 drop per sec. it was clean fuel. I don’t notice it in previous 3 flights. Quote
carusoam Posted July 30, 2019 Report Posted July 30, 2019 Siri made your sentence hard to understand... So now I’m guessing... but, this would be my next step... Be on the look out for two fuel pumps... both have drains... The drains aren’t normally used, until a pump seal leaks... Chase the leaky tube to its origin... and now you know the source... Take pics and share... if it is a leaky pump drain... the pump can be OH’d or resealed... Are you getting any transition training with your new 2 U plane? Typically a Mooney specific trainer should be able to point out sniffle valves, and fuel pump drains... there are other drains in the same area... one for battery acid, and another for oil that escapes the case vent... PP thoughts only... Best regards, -a- Quote
takair Posted July 30, 2019 Report Posted July 30, 2019 It is somewhat normal to drip a little fuel from the sniffle valve that Anthony mentioned. It is a metal valve in the bottom of the engine case, routed to the bottom of the cowl with a rubber line and then exits through a metal line. It is generally excess fuel from the injectors (assuming you are fuel injected). Alternately, you may be dripping fuel from the fuel pump line....this would not be normal. Figure out which line, likely the sniffle line. 1 Quote
Yetti Posted July 30, 2019 Report Posted July 30, 2019 Search Don Maxwell website for Sniffle valve Or you need a new mechanical fuel pump Do a leak down test Quote
Ragsf15e Posted July 30, 2019 Report Posted July 30, 2019 You’re gonna need one of the AP guys here to help you out with specifics, but there are lots of drain tubes in that location, picture might help. There is a drain for both fuel pumps, the intake manifold, and the oil vent line are all in that area. Quote
Yetti Posted July 30, 2019 Report Posted July 30, 2019 Leak down test. mixture closed. Elec fuel pump on. Open mixture. Count to 6 Close mixture. Watch Fuel Pressure gauge. Should hold pressure for a minute or so. If it goes down you need a new mechanical fuel pump Get a new one. Only a few bucks more than rebuild. Quote
Yetti Posted July 30, 2019 Report Posted July 30, 2019 If you are leaking out the fuel out the sniffle you should lean agressivly on the ground. As in landing role out. Pull to 1/3 open on mixture. Open door. It's summer time in Texas afterall. Quote
Newowner Posted July 30, 2019 Author Report Posted July 30, 2019 Thanks for your responses. I’ll do more research and take pict. next time I fly. I’ll do that test time I’m at the airplane. Also tach seems shows way to high on rpm. On TO it was reading almost 2800. Quote
carusoam Posted July 30, 2019 Report Posted July 30, 2019 Newowner... an over rev is an expensive challenge... Look up as quickly as you can... how Lycoming handles various rev limitations... how much and how long... Any training with the new bird at all? Best regards, -a- Quote
Newowner Posted July 30, 2019 Author Report Posted July 30, 2019 I used to fly 231 years ago. I don’t think it’s the engine. It sounds and feels normal on TO roll. It might be tach indication. I just ordered electronic tach. Prop and hub is brand new. previous owner replaced them before selling it. Quote
Newowner Posted July 30, 2019 Author Report Posted July 30, 2019 She was sitting in the hangar for last 8 years, but went through annual in February. I guess I’ll have to work all this little bugs, hoping without landing off an airport. Quote
carusoam Posted July 30, 2019 Report Posted July 30, 2019 Use the iPhone (or other) for an app that uses sound to determine rpm of the engine... Prop and hub should probably be set up with the Governor... the gov is adjustable... Don’t be afraid to find transition training... the fun things that you can relearn in an hour may save you from having an engine OH... Learning this stuff from a guy on the internet is... sub optimal. PP thoughts only, not a mechanic... Best regards, -a- Quote
Newowner Posted July 30, 2019 Author Report Posted July 30, 2019 I’m ok to fly it (over 11000 hrs). Just never owned an airplane and now dealing with busy APs. So close to start fixing it myself Quote
carusoam Posted July 30, 2019 Report Posted July 30, 2019 I assumed you had tons of experience... Just not the kind that will save you a few bucks and a few hassles... We Get Many new owners that some times resist the idea of transition training... some fly jets for work... I sell machines for a living... customers prefer transition training on their ninth machine, as well as their first... Call it learning tricks of the trade... or reviewing tricks of the trade after some time off... Wasn’t trying to undercut your experience... Just trying to save you some hassle, with a proven approach... I have also sat through a great presentation given by a fighter pilot who stalled a Mooney on departure... Now, if you said you had 11k hrs in an M20F... i’d Still be asking the tough questions... Airplane ownership is interesting... none of it gets taught in flight school... While you have time... Use the search function to look up Transition Training to see what it is about... Avoid being my fighter pilot friend... Best regards, -a- Quote
Newowner Posted July 30, 2019 Author Report Posted July 30, 2019 I did fly for 3-4hrs with my friend on it before I bought it. Plus I used to instruct in 231 about 10 years ago. But I’m always like new tricks and advises from other pilots. Sent from my iPhone using Tapatalk Quote
carusoam Posted July 30, 2019 Report Posted July 30, 2019 Where are you located? Are you familiar with MAPA? There is a MAPA training coming up at KACY, I believe. I Nice lower cost way to get familiarized with your bird.... Can Cut a chunk off your insurance cost. Is personalized for your needs... If you are going to fly the bird IFR... it is helpful to get the details in the MAPA book that comes with the course... Are you familiar with GA instrumentation? Want to get some modernization going? Your F, Probably has the original tach? Does it give a steady reading, or is it bouncing? Signs of wear... easy to update... choices of about four vendors... are you interested? Didn’t your K have a sniffle valve too? Typical of fuel injected engines... Best regards, -a- Quote
Yetti Posted July 30, 2019 Report Posted July 30, 2019 You don't want to over rev. You don't want the prop tips going super sonic. There are aps for you phone that use sound to check RPM. There are optical tachs for the model airplane market that are quite accurate. The higher you go the easier it is over rev the engine. Quote
Newowner Posted July 30, 2019 Author Report Posted July 30, 2019 Thanks Yetti. I did order optical tach and will check RPM next time I fly it. Sent from my iPhone using Tapatalk Quote
Newowner Posted July 30, 2019 Author Report Posted July 30, 2019 Carusoam, thanks for the info. I wish I have more time to attend it. I’m in San Francisco and only be flying it within 150nm range to commute. Not planning to fly it IFR at all at least for now. Sent from my iPhone using Tapatalk Quote
carusoam Posted July 30, 2019 Report Posted July 30, 2019 MAPA typically sets up four weekend events around the country each year... One of the days is heavy on owner supplied maintenance... a great way to get up to speed with what you have... meet some similar Mooney owners and make contact with other people that may be helpful for what you are trying to learn... Mapa has a web site that covers the details... Check the download section around here... you should be able to come up with two manuals for your bird... a maintenance manual and a parts manual... these can help you identify what tube has the fuel exiting from it... then compare your bird to the manual... Some planes get altered over the years... Best regards, -a- Quote
David Lloyd Posted July 30, 2019 Report Posted July 30, 2019 As others have said, there are drains for the sniffle valve and mechanical fuel pump. The only time I see raw fuel drip from the sniffle valve drain is when I flood the engine on a hot start. It may drip a little at shut down, I just have not seen that. But it is normal to drain any liquid from the intake manifold, that's what it does. If the mechanical fuel pump is leaking fuel, it has failed and will soon become catastrophic. You need to know which drain is dripping fuel. 1 Quote
PT20J Posted July 31, 2019 Report Posted July 31, 2019 Sniffle is to drain intake of excess liquid fuel. If sniffle drips after shutdown using mixture control to kill engine by starving it for gas, you’ve got to ask where the fuel is coming from to get into the manifold? Quote
Newowner Posted July 31, 2019 Author Report Posted July 31, 2019 That’s exactly what I was thinking. I always taxiing lean and shutting down at 1200rpm with slow mixture pull. Sent from my iPhone using Tapatalk Quote
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