Prop leaking… sometimes?

[KHyde]

Prop was last overhauled in 2004. Resealed in 2011. It’s got about 1200 hours on it. When we bought it a couple of years ago it had some grease that would sling out on the prop (3 inches or so). I’m new to GA aircraft and was advised it wasn’t a big deal. I’ve asked a few mechanics about it every now and then and they’ve always said we cleaned it off really well. Just keep an eye on it (bad if there’s more leaking and bad if it stops leaking). When I mentioned it to Savvy they said if McCauley is leaking moisture can get inside and corrosion can develop and not to ignore it forever. 
 

It just came out of annual today and I didn’t notice any grease  on the prop after flight, but it doesn’t seem to leak every flight.

I’d love some advice on overhaul vs. keep waiting vs. top prop conversion. 
 

 

[Yetti]

tell us the plane or the prop.    Unless you are getting prop grease on the windscreen.   Not to worry.    Also there was a problem with Aeroshell 6 grease.  use Aeroshell 5 instead. 

[MikeOH]

I’ve had the same issue since I’ve owned my F. I have a Hartzell 2 blade with the non-AD hub. I had the prop overhauled and it still leaked! Sent it back…still leaked! Flew for a few years and sent it in again…guess what? Yup, still leaks! But, now only one blade, and it’s less.

I’ve pretty much resigned myself to just living with it

[KHyde]

1 hour ago, Yetti said:

tell us the plane or the prop.    Unless you are getting prop grease on the windscreen.   Not to worry.    Also there was a problem with Aeroshell 6 grease.  use Aeroshell 5 instead. 

It’s on the prop. Definitely not on the windscreen.

[KHyde]

1 hour ago, MikeOH said:

I’ve had the same issue since I’ve owned my F. I have a Hartzell 2 blade with the non-AD hub. I had the prop overhauled and it still leaked! Sent it back…still leaked! Flew for a few years and sent it in again…guess what? Yup, still leaks! But, now only one blade, and it’s less.

I’ve pretty much resigned myself to just living with it

Well dang. I’ve heard similar from a friend on the field. Once I realized how many years it had been since overhaul it got me a little rattled, but I guess it’s somewhat common. 

[PT20J]

The McCauley manual says to cycle the prop all the way to the low speed/ high pitch stop a few times. I did this and it stopped my minor leaks. 

[takair]

I have come to the opinion that if you service the prop every annual, it eventually gets full (12 years or less if over serviced) and further grease needs a way out.  Seems to coincide with recommended OH time.  So, full hub….some migrates out the seal.  The risk of not servicing is corrosion in the hub and/or dried grease.  So, it’s possible you simply have a slightly over serviced hub. The grease breaks down and the oil seeps out.  As Yetti said, Arroshell grease got worse over time and is no longer the preferred grease after overhaul.  

[MikeOH]

Mine was overhauled around the time of the Aeroshell issue. But it leaked before and after, so who knows?

I think Nyco is the new recommendation, but can’t be mixed with the Aeroshell. However, you can mix Aeroshell 5 with 6, FWIW.

[carusoam]

Fresh out of annual?

Fresh grease gets pushed into the hub causing some to escape out the seals…

deep cycling the prop?

another reason some grease may get past a seal that has been sitting awhile…

 

when grease comes out three inches of prop blade…

it will leave small bits of grease on the windscreen…

a clean windscreen is required to see it…

 

let’s invite…

@Cody Stallings

for some insight on prop grease leaking…

 

Best regards,

-a-

[PT20J]

The OP said he has a McCauley prop. Those get greased only when taken apart. There are no external grease points like a Hartzell prop.