prop seal changed, still seeing oil. normal?

rbridges

rbridges

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I had the seal and o-ring changed a month or so ago. I was still getting a little film on the windshield, so they were inspected and reseated. I have about 10 hours on them now. I wiped the area down really well and flew 2 more hours this weekend. This is what I'm still seeing. Is it normal to still get a little oil? I spoke with the IA shortly after they reinspected it, and he said some oil may get blown into the area since it's impossible to get 100% of it cleaned after removing the prop. I'm not seeing anything on the windshield, but I don't know if this is typical or not. Could oil still be seeping from the hub area? BTW, it's a mooney with O-360. The pic of the shop towel is to show how much I found after today's flight.
 

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I know this doesn't answer your question very well but here is my experience that is loosely related. I had a prop that essentially had dry rotted seals. It didn't have too much time on them but too many years. It puked out on a flight and I brought it back home and taxied to my shop. I had them send both out for O/H. They came back with zero time logs. After installing I haven't had a single drop out of them with several flights and hours on them.

Hopefully you can get some better answers from people who have just had them re-sealed or some mechanics experience. Good luck.
 
My mechanic has told me in 2010, 2012, 2014, 2016 and 2017 that my prop seal was leaking. In 2014 I objected and said you replaced it two years ago -

"yeah yeah yeah, blah blah blah, it can fail you flew it alot"

In 2016 I objected again - and he "blah blah blah you didn't fly it alot"

So I stood there with him when they disassembled the prop seal and the seal was turned in the channel - so of course it was leaking.

"Blah blah blah its hard to put the seal in properly, and simply bolting it back on blah blah blah" but I didn't pay for it.

Then this past annual again - a leak.

"maybe its the front crank seal - blah blah blah"

Took the prop off - and it turned in the channel again - same place.

"Well, that guy left last year, maybe he wasn't putting the prop back on right, we'll see what happens this year. . . .' Thankfully I did not pay for it again. This time I had the factory manual present and it called for a series of bolt tightenings with the prop at specified locations: Bold Print - "Do not simply tighten the prop bolts or the seal will turn in the channel"

If you don't understand what you are being charged for - you will literally hear every single possible excuse. You simply cannot be an aircraft owner without being inherently suspicious.

Hell - I had bushing at the end of the aileron cable wear- you need to replace that when it happens. But the thing comes back with the aileron noticeably out of rig when the yoke is neutral. How does that pass IA inspection?

These guys are usually pretty good- and the misrig happened when I had someone else do the annual to get another set of eyes on the airplane. . .
 
The oil seal inside the the propeller bore where the crankshaft mates or the blade seals? Or you talking about the crankshaft seal? Correct terminology is important.
I saw this post on mooneyspace (not a member) that's the place to get some really bad information.
 
Yeah, I'm not 100% on terminology .I believe they changed the crankshaft seal and an o-ring on the prop .they took the prop off a second time and inspected everything. I'm still seeing oil in the area. Not as much, but still showing up. I think the crankshaft seal is still leaking but I didn't know if I should give it a little more time .
 
You are much better off having someone that knows what they're doing look at it rather than seeking solutions on a forum.
 
Paulie said:
You are much better off having someone that knows what they're doing look at it rather than seeking solutions on a forum.
Click to expand...
I agree but it's an hour flight each direction, and it's not easy for me to plan. I was just trying to get some opinions .
 
Prop shaft seals are not easy to replace at the best of times. You need to follow the instructions to the "t", and even then it still might not be successful. And also don't rush the job! I haven't changed one on a piston in a very long time, but I think it was last year for one on a PT6. Same basic procedure.

I would be more upset about them not installing the prop correctly! That fan up front is pretty important!
 
JAWS said:
Prop shaft seals are not easy to replace at the best of times. You need to follow the instructions to the "t", and even then it still might not be successful. And also don't rush the job! I haven't changed one on a piston in a very long time, but I think it was last year for one on a PT6. Same basic procedure.

I would be more upset about them not installing the prop correctly! That fan up front is pretty important!
Click to expand...

I hate people that are "google" experts on a topic, but I looked at the lycoming service instructions. It looks like it pretty specific, and I'm worried that it may need to be replaced. Removing old sealant, avoiding scratches, using correct new sealant, cure time, etc. Looks like there are lots of fail points in the procedure. They didn't charge me for the second time, but time and fuel costs do become a factor. Very frustrating.
 
First, you need to determine if you are seeing OIL or grease. A lot of props throw grease after servicing, especially because a lot of dolt mechanics can't or won't bother to read the proper procedure for doing so.

And as JAWS says (google expertise or not), dolts also screw up the prop seals. Some of the mating surfaces are spec'd have the seal applied dry on the metal and these guys harken back to their shadetree oil change procedure of wetting the filter gasket with oil and then they can't figure out why the thing leaks.
 
Thanks, Ron .it's definitely oil. I'm going to call and talk with the guy who did the seal .
 
When my first prop seal started leaking on the 172 I had at the time the A&P at the out of town airport I was at that replaced it didn’t rough the proper shaft per the instructions and it started leaking again after about 10 hours. When my regular IA showed me how to do the same job he pointed out the A&P’s error, said it was common,and that it would leak every time if that step was skipped. It never leaked again the entire time I owned the plane.

Gary
 
Thanks, everyone. I've decided to fly it a few more hours and see if I keep finding oil. I'm going to have someone local do it this time. By the time you factor in getting a ride to drop off the plane and going back to get it, there's a few hundred dollars worth of fuel involved every time. That doesn't count the aggravation involved. I know, first world problems. lol.
 
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