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found oil on the floor, grounded

I have always put a hole at the elbow going into the case. I don't care if there is no chance of it freezing, maybe it could clog by some other magic reason. A small hole is good redundancy and piece of mind for me and a requirement in Canada as already mentioned. It sure doesn't hurt anything by doing it.
 
Been there fixed that

I, and several others that run the Superior engines, have had front seal failures. We have all found that the front seal was installed with white silicone sealant. I am not sure what you mean by "the same color as lead" but white flakes is what we all had. New seals and plio bond adhesive were the answer.
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My front seal on my Superior IO360 leaked after a 100 hrs or so. Pulled the old out and it was "bonded" with the white silicone sealant as well. Didn't take much force to unseat it. Installed a new seal with pliobond. No issues in the last 200 hrs.
 
defeat mythology!

I'm really glad to see Scott and BillL and a few others speak up with reason and data to combat what is a periodically surfacing piece of mythology.

One poster said, "what can it hurt?" and I think the answer is that it will spray a small amount of blow-by around inside the cowl where I don't want it. Which is, after all, why the breather hose dumps it out at the cowl cooling exit -- to get rid of it.
 
Putting the seal in boiling water will make it more pliable and stretch over the prop hub more easily. I had a front seal on my Cherokee (0-320) blow out in cold weather. On approach to landing the vent probably froze up and the seal puked out when I throttled up to taxi. We put a "blow cock: in the vent tube to help prevent that. I would get rid of the hose near the exhaust and put a metal tube near the exhaust to keep the vent tube warmer.

Roberta:)
 
Putting the seal in boiling water will make it more pliable and stretch over the prop hub more easily. ...stuff deleted...

Roberta:)

Another trick that I used putting my front seal in was to put a plastic grocery bag over the prop flange. The combination of a warm, pliable seal and the slippery surface of the plastic made the installation of the seal dead simple.
 
I LIKE !!

Another trick that I used putting my front seal in was to put a plastic grocery bag over the prop flange. The combination of a warm, pliable seal and the slippery surface of the plastic made the installation of the seal dead simple.

And less chance of damaging the seal from surface finish on the flange. I'll remember this idea for the future. Thanks for tip.
 
cleaning the groove

My front seal started leaking in my Superior XP engine at about 300 hours. I replaced it and no more leaks so far at 1100 hours.

Lycoming sells a seal tool to help install the one-piece seals but they are $1150 to $1200. I bought the Aircraft Tool Supply version (5209) for $80 and it worked very well. Took much longer to get the seal seating area completely clean (working in tight space behind the flange) than actually replacing the seal itself.

Andy

acetone is recommended for cleaning
 
Steve, are you using the Antisplat crankcase check valve installed on the breather hose?

Steve doesn't appear to be using a crankcase evacuator from Anti-Splat...but if you do use any kind of evacuator connected to the exhaust, install a safety check valve. It eliminates the possibility of pushing out the front seal if the exhaust tap cokes shut.

http://www.vansairforce.com/community/showpost.php?p=920007&postcount=227

I am not aware of a single incident with any RV where a frozen vent tube was suspected as a cause, if the installation was done per the plans with the tube up inside the cowl. This keeps the entire tube in an area too warm for ice to form.

I can try to grab some addition temps in sub-freezing wx but I'm certain the lower cowl temps anywhere inside the loser cowling will still be above 100*F.

Lowest cowl exit temperature measurement I've ever heard was 120F.

If by recommended you mean by Lycoming, I am pretty sure that the number 1 product recommended by them is a Pliobond adhesive.

Certainly recommended by the best engine builder I know.
 
Some where, I think on this web site a guy made an install tool with a few pieces of PVC pipe. Lot less than $80.

I have changed many in the past using a plastic bag,3 Phillips screw drivers, lubed down the bag with gear oil, warmed the seal with a hair dryer. Just make sure to clean the seal off and the inside bore where the seal goes with something like acetone, MEK, or even AvGas before gluing the new seal in.

Oh yes: do not forget to assemble the spring and put it into it's groove before gluing the new seal in place.
 
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I also used three round shank phillips screw drivers. I used blue masking tape to cover the flange and give the seal a good smooth surface to slide over. Heated the seal in a Mr. Coffee to install, and gave it a day to relax after that BIG stretch.

I used an old toothbrush with the neck heated and bent 90 degrees to clean the case surface in prep for the adhesive. I used an acid brush with the hairs trimmed down and the neck bent 90 degrees to apply the Pliobond adhesive.

My challenge with the whole project was the seal tension spring. Mine did not hook to itself. One end screwed into the other. You have to pre-wind it, get it into place and release your grip and let it screw into itself....... all behind the flange.

I have had a bone dry seal for over 400 hours now. Do read the Lyc. O/H manual before you do this.
 
method

An A&P coached me thru the installation.

1. Clean the alum seating surface with grey scotch brite to remove any previous residue. Also, you can use MEK to help if needed. I didn't need it.
2. Clean alum seating surface with brake cleaner.
3. Visually inspect to verify it's very clean.
3A. Place the rubber seal in hot water.
4. Place some easy release tape on the shaft to protect.
5. Apply Pliobond to the alum horizontal surface but not the aft vertical surface.
6. Remove tape.
7. Hook spring over shaft
8. Apply a very light coat of axle grease on the shaft.
9. Place a short alum tube thru the flange bolt hole.
9A. Place a plastic grocery bag over the flange.
10. Remove rubber seal from the water and hook it over the short alum tube with open channel downwards.
11. Hook the seal stretch tool (90 degree elbow heavy grey conduit with slot cut on the convex side) and stretch the seal around the flange.
12. Work the spring into the seal groove with a 90 degree pic.
13. Coat the outer surface of the seal with Pliobond.
14. Push the seal into place until it engages a small groove. You can feel it seat.
15. Let it rest for 24 hr.
16. Take your A&Ps to lunch, Sam and Ray.

Total time: 1 hr 20 min
A nice learning experience.

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DSCN1126_zps3f4ilzok.jpg
 
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Its lead, you are running a centrifuge there. The lead collects in anything that spins including accessory case gears.

To me it seems like that seal may not have been put in properly as there isn't much sealant and/or the sealant has not stayed on the seal.

The local engine guy we work with recommends 5 minute Araldite for experimental prop seals. He says it works a lot better than the Loaming approved stuff.

thanks

Second confirmation of lead inside the shaft.

My A&P said the grey stuff in there was lead from the fuel.

I looks like lead and feels like lead, heavy.

He said the one way to slow down the accumulation was to be very lean during ground operations.

Wear gloves when cleaning this area. You don't want it under your fingernails. I was amazed how much accumulated in 500 hrs.
 
Now you can come over and replace mine if mine blows when I pre-pressurize the engine in a few weeks. :p
 
One more added step!!!!

An A&P coached me thru the installation.

1. Clean the alum seating surface with grey scotch brite to remove any previous residue. Also, you can use MEK to help if needed. I didn't need it.
2. Clean alum seating surface with brake cleaner.
3. Visually inspect to verify it's very clean.
3A. Place the rubber seal in hot water.
4. Place some easy release tape on the shaft to protect.
5. Apply Pliobond to the alum horizontal surface but not the aft vertical surface.
6. Remove tape.
7. Hook spring over shaft
8. Apply a very light coat of axle grease on the shaft.
9. Place a short alum tube thru the flange bolt hole.
9A. Place a plastic grocery bag over the flange.
10. Remove rubber seal from the water and hook it over the short alum tube with open channel downwards.
11. Hook the seal stretch tool (90 degree elbow heavy grey conduit with slot cut on the convex side) and stretch the seal around the flange.
12. Work the spring into the seal groove with a 90 degree pic.
13. Coat the outer surface of the seal with Pliobond.
14. Push the seal into place until it engages a small groove. You can feel it seat.
15. Let it rest for 24 hr.
16. Take your A&Ps to lunch, Sam and Ray.

Total time: 1 hr 20 min
A nice learning experience.

DSCN1126_zps3f4ilzok.jpg

.
.....This may come in handy and possibly save the day for some folks in the future! Every engine we build, we install a retainer plate, or at least a pair of retainer tabs for the front crank seal. There is actually a Lycoming part number for this retainer plate ( SA641361) and they are readily available. We usually make our own from some aluminum stock. We always drill and tap every engine case that isn't pre-drilled, prior to assembly. As in Steve's case we retrofit the retainer by drilling the bosses (see photos) on both sides of the crank. This can be accomplished with a long drill bit, and an extended tap through the prop bolt holes in the crankshaft. This process eliminates this failure ever happen again under any circumstances. Also we recommend using the one piece seals only, as we have had little success with all the others. We also offer on our website, the crankcase pressure bypass kit that will relieve and control the pressure at .25 psi in the event of a frozen or blocked crankcase ventilation tube. Thanks, Allan..:D
 
I like that idea. There is a convenient boss on the side. I wonder why that's not in the standard build? Is a blown seal a fail-safe for something worse like a blown case? I don't know.

found it
SA641361__64390.1368371226.1024.1024.jpg
 
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I like that idea. There is a convenient boss on the side. I wonder why that's not in the standard build? Is a blown seal a fail-safe for something worse like a blown case? I don't know.

found it
SA641361__64390.1368371226.1024.1024.jpg

...This was standard equipment for many years, and the answer to your question is no! it is not designed to come out. They decided it would be less expensive to just machine a small lock groove in the later cases. Problem is, they do not hold the seal like intended. Many do leak and come out, and unfortunately it only takes just a little positive pressure in a hot engine. If your breather were to become blocked for whatever reason, and pressure began to build in the crankcase. The spot where it will exit is always the dip-stick, and next is valve covers. In our testing this occurred at about 12 to 15 psi. and is a easy fix and easy to find as well. I hope this helps a few people out and saves them some grief. Thanks, Allan..:D
 
Just wondering why there isn't a safety plug, lets say at the top of the dipstick, like a pressure cooker. It can be simply a rubber plug that can let the pressure out and also for easy visible check.
 
Just wondering why there isn't a safety plug, lets say at the top of the dipstick, like a pressure cooker. It can be simply a rubber plug that can let the pressure out and also for easy visible check.

... No engine, aircraft, industrial, automotive or other has ever had this!...:D
 
Fascinating Accident

Only tangentially related to this thread... a fascinating accident... someone grounded a weld wire in the crankshaft ID in order to weld the case and caused a stress riser... it took 14 years for the propeller to leave the airplane... the accident chain could have been broken by paying proper attention to the oil leak at the front seal... OK, really, the wire should never have been grounded there.

"Instead, the pilot purchased the nose seal parts from the engine shop, and he hired a local independent mechanic to install them in his airplane. Upon completion of the maintenance, the mechanic requested that the pilot perform a ground run-up to check for leaks. The pilot declined and took off."

"The propeller assembly was found separated from the engine, aft of the mounting flange."

"A TCM metallurgist examined the fractured crankshaft. The metallurgist reported that about 2.3 inches inside the shaft bore, two arc marks were noted. The examination indicated that the fracture had originated at the site of the arc marks, and it had progressed in fatigue until overload occurred followed by separation of the propeller assembly."

Link
 
... No engine, aircraft, industrial, automotive or other has ever had this!...:D

Well thats NOT true! My old Volvo 122S had a crankcase vent hose that came out of the oil filler cap and connected to the air cleaner. The intent was to recirculate any oil vapors not scavenged by the positive crankcase ventilation valve. The hose I am describing was a fairly loose fit on the oil filler cap. Any slight overpressure of the crankcase would pop that hose off and vent the crankcase.
 
Hence my question of "just wondering WHY"

...This issue only comes up on aircraft engines, at freezing temperatures at altitude,(I've never seen it personally). They don't fix non existent problems on most other applications. On aircraft they use a whistle stop in the breather line.
 
Well thats NOT true! My old Volvo 122S had a crankcase vent hose that came out of the oil filler cap and connected to the air cleaner. The intent was to recirculate any oil vapors not scavenged by the positive crankcase ventilation valve. The hose I am describing was a fairly loose fit on the oil filler cap. Any slight overpressure of the crankcase would pop that hose off and vent the crankcase.

... I guess you are correct! I once had a old car that my pesky neighbor shoved a potato in the exhaust pipe. This action made the loose fitting muffler blow off from the high pressure when I started it up. Surely it was designed this way in case of potato intrusions.:rolleyes:
 
... I guess you are correct! I once had a old car that my pesky neighbor shoved a potato in the exhaust pipe. This action made the loose fitting muffler blow off from the high pressure when I started it up. Surely it was designed this way in case of potato intrusions.:rolleyes:

I guess that's better than the ole "Banana in the tailpipe!":D
 
What service!!

I have the Antisplat air-oil separator installed (without inlet into exhaust). After this thread I wanted to install some pressure relief system should I ever have icing or blockage of the crankcase vent. Whistle hole not possible due to soft silicone (blue) type hose. I could not find the product Allan was referring to on his website (turned out because i did not know what it looked like). I called and in no time I had this pressure relief system sent to me. Received 2 days after call. AT NO COST!!!
Thanks Allan.
Johan


.
We also offer on our website, the crankcase pressure bypass kit that will relieve and control the pressure at .25 psi in the event of a frozen or blocked crankcase ventilation tube. Thanks, Allan..:D
 
grounded again

I suppose it's better to find this on the ground. Weeping starting again at about 100 hrs after replacement using Pliobond. I suppose the Pliobond knew Oshkosh was just around the corner. What's up with these dang seals?

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I've always used Pliobond and so does the maintenance shop at my airport. But I guess you know that Lycoming recommends Dow 737 Neutral Cure Sealant. It's in Lycoming Service Instruction No. 1324C.

I'm not going to re-read the entire thread, but are you absolutely sure it's the crankshaft oil seal? The reason I'm asking is that I hunted for months to find the leak on mine and changed the seal when the real leak turned out to be at the rocker cover gasket on the #4 cylinder. I had over-torqued the R.E.A.L. red RTV gasket. The only way I found it was to add that fluorescent dye to the oil and use a UV light in a darkened hanger. On my long hunt for the leak, I even taped up a butcher paper ring around the crankshaft in front of the oil seal and went flying. I figured that would prove one way or the other whether the oil was coming from the crankshaft seal. It seemed like a good idea, but results were inconclusive since oil was flying all over inside the cowling. Good luck.
 
I used a borescope and could see the oil trail from the bottom of the seal so I'm sure that's the source. I may try the DC 737 instead of the pliobond. I thought we had a done a good job on the replacement so I'm not sure of the root cause of the failure. I added side holes to the breather tube to ensure no over pressure could exist. It's a goofy design to rely on glue on this big seal to keep the oil inside the engine.
 
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Our local engine shop prefers 5 min/high strength epoxy for experimental. They say it virtually eliminates this issue.
 
I used a borescope and could see the oil trail from the bottom of the seal so I'm sure that's the source.
Sorry. I didn't mean to patronize. Was it possible to tell whether the oil was coming from around the crankshaft or from the seal-to-case area?

When I changed my seal, I did some light polishing of the crankshaft with 600 grit wet-or-dry. Interestingly, Continental SB M76-4 advises using emery cloth to scratch a "helix" on the crankshaft under where the seal will be. I assume that is to sling any oil back toward the engine.
 
Did you check the bore size of the seal flange when you last replaced the seal? Lycoming makes a .050" oversize seal for worn bores. https://www.lycoming.com/content/service-instruction-no-1324c As a side note and previously mentioned, Lycoming recommends the Dow 737 natural cure sealant. Do you have access crankcase pressure working the seal loose? I read somewhere that Lycoming used a bolt on retainer ring to hold the seal in on some of their engines. I had a co-worker that was also a pilot and owned a Beech Super Musketeer. The oil seal blew out on him during climb out and he was very fortunate to get the plane back on the runway with the windscreen covered in oil. Fearful that would happen to me, when I replaced my leaking crankshaft oil seal, I made a .062 aluminum split ring that fit the front of the case in front of the crankshaft seal flange. and Pro-Sealed it in place. I had a lot of crankcase blow-by from a couple marginal cylinders. About 50 hours later I decided to replace the cylinders with new power assemblies, but the retainer ring gave me piece of mind.
 
seal keeper

I read somewhere that Lycoming used a bolt on retainer ring to hold the seal in on some of their engines.
Yes, my O-290-D2 with the O-320 crankshaft has one. It's split in two halves and held on with four #8(?) screws. This photo was of my attempt to confirm that the leak was truly coming from the seal. That paper around the crankshaft is a sandwich of butcher paper on the inside and wax paper on the outside. As I recall, after flying the plane with the butcher paper, it was was mostly oil-free but I ignored that evidence and changed the seal anyway (Story of my life...sigh):

tBlsyN.jpg
 
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I used a borescope and could see the oil trail from the bottom of the seal so I'm sure that's the source. I may try the DC 737 instead of the pliobond. I thought we had a done a good job on the replacement so I'm not sure of the root cause of the failure. I added side holes to the breather tube to ensure no over pressure could exist. It's a goofy design to rely on glue on this big seal to keep the oil inside the engine.

Were you able to confirm that the oil was leaking from the OD of the seal, from a compromised glue joint, and not the ID? The crank can wear at the seal location and cause leaking. I would also check the case bore to be sure that it was not machined to a larger bore at some time.

Also, did your case have a small channel machined in the bore? Mine did (O-320) and the seal had a ridge that helped to lock it in the bore.

Larry
 
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history: I replaced the original seal 100 hrs ago (460 hrs total time) because it became totally unseated and was resting on the crankshaft. It was replaced with a similar seal using Pilobond adhesive rather than the original white RTV. Yesterday upon oil change I found it was leaking. The Pilobond is secure and the seal is seated and the leak is between the crank and the seal. There is a black color to the leaking oil but my internal oil is clean so I can only presume the seal is wearing but not sure why. question is: how to remove the seal for replacement?

IMG_20170716_151323_zpsriltxcnk.jpg


IMG_20170716_154559_zpsu5jgpznc.jpg


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Take a cotter pin removal tool, poke it into the seal and pull. Then cut seal with a knife. Make sure to replace the spring with the new one that comes with it. Ensure the spring is fully seated on back of seal before inserting.
 
Take a cotter pin removal tool, poke it into the seal and pull. Then cut seal with a knife. Make sure to replace the spring with the new one that comes with it. Ensure the spring is fully seated on back of seal before inserting.

Thank you and funny that you mention that spring. Some time after installation I realized I got them crossed upon installation and re-used the old spring. I wouldn't think this could be the cause because a spring is a spring right, but I don't have experience with this. I suppose the spring could act as a vibration damper and if not just right the seal could vibrate and wear.
 
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history: I replaced the original seal 100 hrs ago (460 hrs total time) because it became totally unseated and was resting on the crankshaft. It was replaced with a similar seal using Pilobond adhesive rather than the original white RTV. Yesterday upon oil change I found it was leaking. The Pilobond is secure and the seal is seated and the leak is between the crank and the seal. There is a black color to the leaking oil but my internal oil is clean so I can only presume the seal is wearing but not sure why. question is: how to remove the seal for replacement?

IMG_20170716_151323_zpsriltxcnk.jpg


IMG_20170716_154559_zpsu5jgpznc.jpg


IMG_20170716_154856_zps4obylnaf.jpg

Assuming the crank OD surface is clean (no scratches or groove) it sounds like the seal is defective (problem with rubber compound). Suggest replacing the seal with a different supplier. They probably had a bad batch of rubber and you run the risk of getting another from the same batch. Did you grease the ID of the seal during installation? That is a critical installation step for proper seal break in with a rotating shaft.

Larry
 
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Thank you and funny that you mention that spring. Some time after installation I realized I got them crossed upon installation and re-used the old spring. I wouldn't think this could be the cause because a spring is a spring right, but I don't have experience with this. I suppose the spring could act as a vibration damper and if not just right the seal could vibrate and wear.

The spring is a critical component in creating tension for the seal around the shaft, especially as the rubber ages. However, the spring should last for many years and 1000's of hours. Seems highly unlikely that the older spring caused your issue.

Larry
 
The spring is a critical component in creating tension for the seal around the shaft, especially as the rubber ages. However, the spring should last for many years and 1000's of hours. Seems highly unlikely that the older spring caused your issue.

Larry

...unless it got over-stretched during the removal process...
 
Where to get the correct no. for the seal?

Hello

It looks like my front seal is leaking too! About 3 drops per hour ... that is not much, but enough to make a big mess between the intervalls. It runs down to the alternator and starter, drops onto the FAB.

I need to remove the prop to see if it is really the seal or the case halves.

Where do I get the correct no. for the seal and what thread is there for the nose seal retainer? I live in europe and its really hard to get the screws.

It is a TMX-IO-320 from Mattituck.

Thanks alot!
 
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Steve,

On your post #62 on picture #2 I noticed what could be some glue around the lip of the seal?? The Lycoming Service Instruction 1324C warns about not getting ANY glue on the crank while installing. I wonder if glue on crank is causing wear to the seal? I just installed a new seal on a IO-540 2 weeks ago and fortunately it is not leaking. I used the DOW 737 clear.

Good luck!

Phil
 
Steve,

On your post #62 on picture #2 I noticed what could be some glue around the lip of the seal?? The Lycoming Service Instruction 1324C warns about not getting ANY glue on the crank while installing. I wonder if glue on crank is causing wear to the seal? I just installed a new seal on a IO-540 2 weeks ago and fortunately it is not leaking. I used the DOW 737 clear.

Good luck!

Phil

We were careful but it is possible. When I get the old one off I'll have a look.
 
No pictures because I forgot my camera but yes, I had not one but two locations where pliobond was on the shaft under the seal. I'm convinced that was the cause of the seal wear. I don't know how to be more careful with that stuff so the next time around I will use DC 737.
 
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