Hey everyone. When I bought my plane back in April, I noticed that after flying it for an hour or so, there was a fine mist on the windscreen. The prop had recently been resealed and everyone (seller and prebuy inspection) agreed that sometimes it takes a bit for the prop to dry up.

Now I'm about 80 hours further down the road and it's still doing it. It leaks just enough to run down the prop and then mists back to the windscreen. The cowl normally is free from any sign of the oil. It takes the better part of a couple of hours before it affects visibility.

A close inspection revealed a small piece of silicon that was loose and that is the source of the leak. The rest of the prop is dry as a bone.



So, I've talked to a prop shop and they feel confident they can get it resealed for $1,100. I've had others suggest it could be fixed with a little sealant applied to the point of the leak. I figured I'd throw it out here to see what others have done or maybe know some other tricks.

Thanks,
Cory




Sent from my iPhone using Tapatalk

If it had been resealed, I'd be headed back to the shop that did the resealing and give them a chance to save some reputation. I wouldn't have waited in the first place... I've never noticed more than a few minutes to dry up if they were ever going to.
John

Cory,

If you've got a MacCauley this might help. Worth the read either way.

http://www.mccauley.textron.com/sl1998-24.pdf

In another life I was a propeller repairman/ Chief Inspector at a prop shop, for more years than I care to admit.

The threaded series propeller you have was never meant to be oil-filled. It can be difficult to seal. However when the propeller blade is screwed into the hub, it should not be done with silicone. There is an o-ring, (if my memory serves me correctly, A1633-53) that rides up against the blade nut and lock ring. The small slot that you see is where the lock ring has a tang that engages into the hub to prevent it from turning. There are two of them, one is 180 degrees apart from the one pictured.

During installation of the blade into the hub, it is possible for the o ring to be cut or scraped upon assembly, especially if the sharp spots on the inside of the slots were not dressed with a small jewelers file or sandpaper during the overhaul/reseal process. Sometimes a leak takes a while for it to manifest itself by the appearance of the red dyed oil leaking out. It is for this reason that some prop shops have been known to use silicone on assembly. Per the manufactures instructions, this is not to be done. Some shops will apply silicone after the fact around the circumference of the two areas pictured, between the lock ring and hub and also between the lock ring and nut.

It is red dyed oil that leaks out, as a certain amount (varies between 2 and 3 bladed props) is put in through the oil plug hole after assembly.
This will never heal itself in this particular application. (The 200 or threadless series has a procedure to reseat the O rings in the hub in the event that red dyed oil is leaking past them.) It is generally the threadless series that spit make up lube (ore-lube) for a while after reseal or new propellers. They have an external snap ring with a shim and shim carrier that are well lubed with make orelube on assembly.

The propeller shop that worked on the prop should be more than happy to take care of your leak no charge to you. The biggest hassle is removing the propeller and reinstalling it on your aircraft.

The threaded style propeller that you have (C66 or C58?) , the blades are installed after the spring pack-piston assembly and cylinder are installed. Since the cylinder is most likely not leaking, all that has to be done is break the blades loose on a prop bench, remove the silicone and reinstall with new O rings (2 total).

In the event that you take it to another prop shop, what they are quoting is resealing the entire propeller, including the blade nut and ferrule, as well as the piston, piston rod, cylinder gasket, etc. Where you have absolutely determined where your leakage is, a total reseal is not necessary. A good salesman however will twist your arm and talk you into something you don't need. These props have become a hassle, and a lot of shops don't even want to deal with them anymore. It is a simple process to replace the O-rings mentioned. They can immediately pressure test it and you be on your way. Should not take more than a couple hours, including cutting the safety wire loose and removing the 8 screws on each blade holding the dust covers on, allowing access to install the blade removal tool on the blade nuts, and afterwards re- safetying.

In your propeller, the hub was filled with red dyed oil for the purpose of crack detection. These hubs are eddy current inspected at overhaul, to hopefully catch the cracked hub. It is a highly accurate NDT procedure and I can't begin to tell you how many are found, especially on Cessna sprayers with the C98 dual spring pack propellers. In the operating field, history has shown that usually red-dyed oil coming out is not generally because of a crack, but because you never can be sure it is to be taken very seriously.

I'm more than happy to give you additional information if need be.
Richard

Take prop off . Give it to the prop shop and have it fixed correctly. Or you can have it Jerry rigged with some sealant ect. And just keep hoping it will fix itself and stop leaking eventually . ....... ( I've never seen one stop leaking for good on its own )$1100$ seems fair to make it stop to me .

hardtailjohn wrote:If it had been resealed, I'd be headed back to the shop that did the resealing and give them a chance to save some reputation. I wouldn't have waited in the first place... I've never noticed more than a few minutes to dry up if they were ever going to.
John

Hey John, I should have included more history on the prop. It was overhauled by Sullivan's down in Hayward in September 2013. The previous owners sent it back to be resealed in September 2014. In not sure how bad the leak was or from where. Then, it was sent back to them to resealed in September 2015. I bought it in April of this year with 20-30 hours on it since the last reseal job. I talked to Sullivan's and they were clear that they weren't going to do any type of warranty on their work.

I talked to Precision up in Boise and told them all of this. I also sent pics and a video of the hub. They said that the area it's leaking from is common and that they have good success getting them to seal. Keith said that it could be they either didn't use enough silicon or not enough in the right spot. They feel confident they can get it sealed.


Sent from my iPhone using Tapatalk

Barnstormer wrote:Cory,

If you've got a MacCauley this might help. Worth the read either way.

http://www.mccauley.textron.com/sl1998-24.pdf

Thanks. I'll take a look. It is a MacCauley. A C58.


Sent from my iPhone using Tapatalk

richpiney wrote:In another life I was a propeller repairman/ Chief Inspector at a prop shop, for more years than I care to admit.

The threaded series propeller you have was never meant to be oil-filled. It can be difficult to seal. However when the propeller blade is screwed into the hub, it should not be done with silicone. There is an o-ring, (if my memory serves me correctly, A1633-53) that rides up against the blade nut and lock ring. The small slot that you see is where the lock ring has a tang that engages into the hub to prevent it from turning. There are two of them, one is 180 degrees apart from the one pictured.

During installation of the blade into the hub, it is possible for the o ring to be cut or scraped upon assembly, especially if the sharp spots on the inside of the slots were not dressed with a small jewelers file or sandpaper during the overhaul/reseal process. Sometimes a leak takes a while for it to manifest itself by the appearance of the red dyed oil leaking out. It is for this reason that some prop shops have been known to use silicone on assembly. Per the manufactures instructions, this is not to be done. Some shops will apply silicone after the fact around the circumference of the two areas pictured, between the lock ring and hub and also between the lock ring and nut.

It is red dyed oil that leaks out, as a certain amount (varies between 2 and 3 bladed props) is put in through the oil plug hole after assembly.
This will never heal itself in this particular application. (The 200 or threadless series has a procedure to reseat the O rings in the hub in the event that red dyed oil is leaking past them.) It is generally the threadless series that spit make up lube (ore-lube) for a while after reseal or new propellers. They have an external snap ring with a shim and shim carrier that are well lubed with make orelube on assembly.

The propeller shop that worked on the prop should be more than happy to take care of your leak no charge to you. The biggest hassle is removing the propeller and reinstalling it on your aircraft.

The threaded style propeller that you have (C66 or C58?) , the blades are installed after the spring pack-piston assembly and cylinder are installed. Since the cylinder is most likely not leaking, all that has to be done is break the blades loose on a prop bench, remove the silicone and reinstall with new O rings (2 total).

In the event that you take it to another prop shop, what they are quoting is resealing the entire propeller, including the blade nut and ferrule, as well as the piston, piston rod, cylinder gasket, etc. Where you have absolutely determined where your leakage is, a total reseal is not necessary. A good salesman however will twist your arm and talk you into something you don't need. These props have become a hassle, and a lot of shops don't even want to deal with them anymore. It is a simple process to replace the O-rings mentioned. They can immediately pressure test it and you be on your way. Should not take more than a couple hours, including cutting the safety wire loose and removing the 8 screws on each blade holding the dust covers on, allowing access to install the blade removal tool on the blade nuts, and afterwards re- safetying.

In your propeller, the hub was filled with red dyed oil for the purpose of crack detection. These hubs are eddy current inspected at overhaul, to hopefully catch the cracked hub. It is a highly accurate NDT procedure and I can't begin to tell you how many are found, especially on Cessna sprayers with the C98 dual spring pack propellers. In the operating field, history has shown that usually red-dyed oil coming out is not generally because of a crack, but because you never can be sure it is to be taken very seriously.

I'm more than happy to give you additional information if need be.
Richard

Thanks for the good info Richard. It is a C58. The prop shop in Boise said the same thing about it never being designed to have fluid in there. They intend to tear it down and eddy flux it for the very reasons that you stated. It's unknown if maybe something had cracked in the last 120 hours. And I can understand it from there standpoint too. If my shop were to work on it and send it back into the field, I'd want to give it a good once over before putting my name on it. As much as I'd like to just replace the o-rings, due diligence probably dictates that it be given a full bill of health.

I've actually already gotten an appointment to take it in the first of January. I'd really like to just put a 3 blade on it...but that will have to wait a bit.

In my limited dealings with Precision, they have been good. Any other recommendations?


Sent from my iPhone using Tapatalk

"Where you have absolutely determined where your leakage is, a total reseal is not necessary."

Richard, do you know a shop that you could recommend that would approach this from this viewpoint?


Sent from my iPhone using Tapatalk

Sounds like the options are limited to, credit card, debit card, check, or cash. Sorry Cory. Good luck!

Cheers...Rob

richpiney wrote:In another life I was a propeller repairman/ Chief Inspector at a prop shop, for more years than I care to admit.

The threaded series propeller you have was never meant to be oil-filled. It can be difficult to seal. However when the propeller blade is screwed into the hub, it should not be done with silicone. There is an o-ring, (if my memory serves me correctly, A1633-53) that rides up against the blade nut and lock ring. The small slot that you see is where the lock ring has a tang that engages into the hub to prevent it from turning. There are two of them, one is 180 degrees apart from the one pictured.

During installation of the blade into the hub, it is possible for the o ring to be cut or scraped upon assembly, especially if the sharp spots on the inside of the slots were not dressed with a small jewelers file or sandpaper during the overhaul/reseal process. Sometimes a leak takes a while for it to manifest itself by the appearance of the red dyed oil leaking out. It is for this reason that some prop shops have been known to use silicone on assembly. Per the manufactures instructions, this is not to be done. Some shops will apply silicone after the fact around the circumference of the two areas pictured, between the lock ring and hub and also between the lock ring and nut.

It is red dyed oil that leaks out, as a certain amount (varies between 2 and 3 bladed props) is put in through the oil plug hole after assembly.
This will never heal itself in this particular application. (The 200 or threadless series has a procedure to reseat the O rings in the hub in the event that red dyed oil is leaking past them.) It is generally the threadless series that spit make up lube (ore-lube) for a while after reseal or new propellers. They have an external snap ring with a shim and shim carrier that are well lubed with make orelube on assembly.

The propeller shop that worked on the prop should be more than happy to take care of your leak no charge to you. The biggest hassle is removing the propeller and reinstalling it on your aircraft.

The threaded style propeller that you have (C66 or C58?) , the blades are installed after the spring pack-piston assembly and cylinder are installed. Since the cylinder is most likely not leaking, all that has to be done is break the blades loose on a prop bench, remove the silicone and reinstall with new O rings (2 total).

In the event that you take it to another prop shop, what they are quoting is resealing the entire propeller, including the blade nut and ferrule, as well as the piston, piston rod, cylinder gasket, etc. Where you have absolutely determined where your leakage is, a total reseal is not necessary. A good salesman however will twist your arm and talk you into something you don't need. These props have become a hassle, and a lot of shops don't even want to deal with them anymore. It is a simple process to replace the O-rings mentioned. They can immediately pressure test it and you be on your way. Should not take more than a couple hours, including cutting the safety wire loose and removing the 8 screws on each blade holding the dust covers on, allowing access to install the blade removal tool on the blade nuts, and afterwards re- safetying.

In your propeller, the hub was filled with red dyed oil for the purpose of crack detection. These hubs are eddy current inspected at overhaul, to hopefully catch the cracked hub. It is a highly accurate NDT procedure and I can't begin to tell you how many are found, especially on Cessna sprayers with the C98 dual spring pack propellers. In the operating field, history has shown that usually red-dyed oil coming out is not generally because of a crack, but because you never can be sure it is to be taken very seriously.

I'm more than happy to give you additional information if need be.
Richard

Awesome post - this is what online forums should be like. Great stuff Richard.

OregonMaule wrote:Sounds like the options are limited to, credit card, debit card, check, or cash. Sorry Cory. Good luck!

Cheers...Rob

Hehe...yeah, it could be worse though.


Sent from my iPhone using Tapatalk

You might give Mike at AC Prop in Seattle a call 206-762-1225.
I've had him work on a couple props for me over the years & he's a straight shooter.

hotrod180 wrote:You might give Mike at AC Prop in Seattle a call 206-762-1225.
I've had him work on a couple props for me over the years & he's a straight shooter.

Cool. Thanks for the info.


Sent from my iPhone using Tapatalk

Update:

So, I finally got the prop sent up to Precision Propellers in Boise so they could reseal the prop. First off, they were great to work with. They knew it was coming and turned it around in 2 days. I've used them before when I was in a flying club and just as then, their customer service was great.

Now, for the prop. We got it back on last week and today was my first chance to fly it. First, I ran it for 12 minutes, letting the oil get warmed up and then, at the end, did a normal run up and cycled the prop. I then shut it down and got out to inspect it. No signs of any fluid. So, we loaded back up and took off for a short 30 minute flight.

Back on the ground, inspection of the back of the prop showed signs of something being flung onto the back of the blades. Not a lot, but enough to leave a half an inch to an inch tracks. One was very thin and about 6" long. Both sides showed signs, although very light.

I'm going to call Precision tomorrow but thought I'd ask the same questions here. What is to be expected? Should I expect some initially off of a resealed prop? As was mentioned above, this isn't one of the types that will dry out. I think it's too early to be discouraged. The plan is to wipe it down, fly it, and recheck.

Thoughts?


Sent from my iPad using Tapatalk

It is common on a freshly overhauled or new propeller for make up lube to be thrown off for a bit. On a threadless style (200) series, etc more so than your older threaded propeller (C58). The 200 series has the snap ring with the shims under it right out where you can see it. It is common for these to spit and sputter for up to 20 hours or so.

Your propeller has a felt dust seal underneath the two cover plates held on by the 8 safetied screws (per blade). The make up lube (orelube), usually doesn't come out near as bad as the threadless as mentioned above, but there is some.

However, the main o ring that seals between the blade nut and hub, (This was your initial problem, it was coming out of the lock ring notch),
is heavily lubed on installation, so that it doesn't get cut as the propeller blade nut is screwed into the hub.

You can wipe the residue that you see on the blade with very fine toilet paper or kleenex and try to determine color. I highly suspect it will be black, if so definitely not a problem. If it is reddish tint, you may have an issue, but i doubt it. After the propeller is put together, a low pressure test is accomplished first, followed with a higher pressure test of the hub through the oil plug hole. It is only after it passes, that the hub is filled with red dyed motor oil for crack detection/lubrication.

One thing you could do also is remove the spinner and check for a larger accumulation there. Chances are if you clean up what has flung around in the spinner it will dry up fairly quickly.

Just a few thoughts at the end of a long day.

Richard

Richard,

Thank you so much for the insight and advice. I'll be back at the airport tomorrow and will follow it. I'll let you know how it goes.

Cory


Sent from my iPad using Tapatalk

Cory, I had my McCauley re sealed after it sprung a leak in IDaho... it seeped for about 25 hrs after I got it back... Shop said don't worry about it.... some seepage is normal for about that time....

OregonMaule wrote:Sounds like the options are limited to, credit card, debit card, check, or cash. Sorry Cory. Good luck!

Cheers...Rob

Rob,

That was funny! Sorry Cory for the humor at your expense.

Kurt

No problem Kurt. It was funny!

Thanks Butch! Good to know.

Rich, I made it out today and flew it for a few hours. Before I flew it, I pulled the spinner and took a Kleenex and wiped things down. For,the most part, it seems it had a dark color to it. A couple of damp spots seemed to have maybe a tint of red, but very dim, so I'm not sure about that. Around the edge of the plate behind the prop, it was a little damp but the color looked more golden yellow/light brown...like fresh oil. From the hub, I saw one place where it had streaked...and it was black. After I got done flying, I could see some streaks on the back of the prop as well as on the windscreen. None of it gave a red color. It was all more black and seemed more greasy than oily like it was when the red dyed oil was leaking. I'm thinking, and hoping that this is just cast off from the reseal. The feel of it, as well as the amount is definitely different...and less. I'll continue to wipe it down and recheck it.

Oh, also, I went over the hub very closely before I flew with a bright light. Before I had it resealed you could definitely tell where the red dyed oil was. It would catch the light and really stand out. I saw no red dye whatsoever.

Here some pics from today before I flew it.











Sent from my iPad using Tapatalk