Mysterious Oil Leak?

[TopCatGr58]

Well,

This last fall when I was riding at T.W.O., Godzilla developed a nasty oil leak, I was dropping a quart a day! And with the "few" reports of the SOFA's developing leaks, I just assumed that mine had finally developed the same, although I had mounted and sealed the plate very well, and seemed to have held for over 2 years!?!?

Well, I finally drained the remainder of the oil today, removed the filter, and prepared for a battle of removing the SOFA....from the horror stories from SNOW !

I cleaned it off very well removing lots of oil laden crud, road grime, etc.! I then attached my rubber strap wrench onto it, .....
slip, slip, slip, .. no decent gripping force!

Then I tried positioning a couple of bolts into the oil filter supply holes and a pry bar to try to turn it.....NADA...bent the bolts!

Then, realizing that even though my plate was an earlier version with the recess milled out all the way to the edge, it was still over 3/8" thick out there! So...I took my trusty Dremmel, and cut a nice vertical slot/wedge into the side of the SOFA in the front between the exhaust headers. I then took a nice piece of angle iron, and just a standard claw hammer, and hit it few time and it broke the plate loose, and I was then able to remove it using the strap wrench...still had locktite on the threaded part, but was able to get the MAIN adhesion surface broken free WITHOUT destroying the SOFA, just a little BLEMISH!

But, after removing it, I inspected the sealing surface and it had NO SIGNS of any failure or leakage past it to the outside!? So... it appears I removed my SOFA for naught...but at least I can now put an O-ring groove in it!

So...further investigation was needed to find the mystery leak! I checked the tranny pan bolts, all snug. The clutch cover bolts were also snug and the gasket dry! The leak I had seen during the ride was on the right side near the front of the engine, spraying onto the right lower frame rail beneath the ALT cover!

AHA! It appeared relatively dry around the bottom "VENT" hole, but there was a little presence of residual oil film there! So I removed the ALT cover, bone dry around the Stator and inside, EXCEPT the little chamber where that oil galley plug and O-ring resides, hmmmmm?! **Gratuitous photo moment**





So, I pulled that little plug, and proceeded to get slightly slimed by the oil still behind the plug, wiped off easily! Upon inspection, the O-ring appeared to have gotten flattened from the 25+ years of heat and pressure! I rushed to my local hardware store just 15 minutes before they closed!

I had premeasured the ring with my digital calipers, about 2.5mm wide, but only ~2.15mm thick...yep, flattened. I checked their METRIC neoprene O-rings, didn't have the 13mm ID size needed, so found some 3/32" thick and 1/2" ID and bought it...whopping 29 cents with tax! Fitted it onto the metal plug, and resinserted it back into the oil galley hole, and reinstalled the ALT.

I'll be cutting the O-ring groove tomorrow, and will then reinstall the SOFA....BTW I was able to get some BUNA-N replacement O-rings that I'll be able to provide with the SOFA's so folks won't have to use their old oil filter one, or buy a new filter for just the new O-ring!!!

Well, I hope this is/was the real leak, otherwise, I'm looking at the Tranny pan, hope not!?
T.C.

[rover]

TC, in the photos, where is the plug and o-ring you talk about? My engine leaked a bit of oil, but I cleaned around the SOFA, and there is no sign of seepage. The amount is so small, I'll probably never find the source unless it gets much worse. So you are using o-rings on the SOFA's now? I had contemplated putting a groove for a ring in mine, but it appears to be holding perfectly, so unless I can see that it leaks now or in the future, I will leave it alone. Let us know if and where you find your leak. Thanks for so many things, Rover

[79XS11F]

My engine also developed a small leak from the front lower ALT side after the rebuild. I was smelling oil burning on the pipes and finding oil on the down wind parts. It however only leaks when the engine is running. I do believe this leak is coming from that plug. I put a new O-ring on it of the closest size I had on hand. I have not used the bike since doing this so I am not sure if it cured the leak. I wanted to know if it mattered how far into the hole the plug is pushed and is there oil at pressure behind that plug?
Rob

[John]

That plug is in the main oil galley that supplies oil to the main bearings. It doesn't matter how far you insert it into the hole, the oil pressure behind it will seat it against the alt cover, and that is what retains the plug in position. Don't run the engine without the alt cover on, or the plug will blow out and all the oil will pump out in a heartbeat. A clever man could rig up a way to retain the plug and still run the engine to check the seal for leaks. I had to do just that to verify a leak that I had at the crank seal (twice).

[TopCatGr58]

Hey John,

That sounds like a "slick" idea. There's a bolt hole right next to the plug, a simple piece of steel plate with a hole for the bolt should fit over it, might have to drill a small hole where the plug fits since it sticks out farther than the mating surface of the case, and use washers to place over the plug end so that it just makes contact with the temporary plate without allowing it to get pushed out to far by the oil pressure! And running the engine for a few minutes WITHOUT the ALT on shouldn't cause any problems, I have a battery charger!

Rover, IF the SOFA's are installed correctly the first time, then I don't see any need to remove it. As I stated, after removing mine I could see that it HADN'T leaked, and that was after 3 years worth of hard riding! I just wanted to remove it to see if I could find a better LESS DESTRUCTIVE way of getting it loose for those folks who have the earlier non O-ring version in case they have to split their cases for some reason!

Rob, you may want to either do this test, or ensure your O-ring is 2.5mm or 3/32" thick. If it's too thin, then it may not provide the proper sealing affect, and like John said, it's off the main galley to the crank, not good for a failure there!
T.C.

[trbig]

I don't know how many of those o-rings on the galley plug I have replaced, and they never seem to last. I have finally had enough.. I am going to pull the galley plug, and in behind the plug where it narrows up, I am going to tap and install one of these allen plugs like I did to the YICS tubes on my head..




I have no idea why they didn't make a better system than that plug... you don't ever need in there for anything. I'm so sick and tired of the oil all over my right boot... but it does help keep my boots waterproofed for when it rains! lol. I even tried to put a wad of cardboard under the alt cover to keep the plug pushed in good and tight... still didn't help. I tried Yamabond, teflon tape... nothing seems to stop it for long. I bet this will!!


Tod

[DeanR]

Like Rover, I'm not quite seeing the oil galley plug and o ring that you guys are talking about in TC'c picture.

[rover]

O K, I think I see the one. In T C's upper picture, it has to be the round aluminum button right in the bottom center of the picture, with what looks to be a black ring around it. Not screwed in, just held in place by the alternator cover. I think that is seeping on mine, cause I found about a teaspoon of oil on the floor under the bike. I cleaned all around the SOFA, and there is no sign of a leak. I have the early SOFA with no o-ring, but I am positive that it does not leak. I followed T C's instructions to the letter, and everything worked just fine. I traded some parts for this SOFA from someone who said his leaked. The only thing I did differently was cut off about an inch of the tube AFTER I installed the adapter, cause it stuck out below the plate about 2 inches. I can't see that there is a possibility of this ever leaking short of a very heavy blow to this area by something. When I work on installing the alternator mod, I think I will takes TRBIG's advice and tap and install a plug in this gallery. My mod will require removing that cover, and making another to mount the alternator to. Thanks again, T C, you always seem to come through with what most of us need.

[oldbiker648]

Dean,
Look at the bottom center of the top photo. At about 2'oclock above the screw hole is the plug with the round projection. The o-ring apparently seals the plug into the galley. If you look at the lower photo you can see the shiny spot on the cover where the projection at the center of the plug hits the cover. It does appear to be a bit of a mickey-mouse set up and I like the idea of a threaded plug much better.

[oldbiker648]

ya beat me to it, Rover...

[rover]

Well, I finally won a race, other than the many I won against Harleys.

[DeanR]

Got it. Thanks guys. No leaks on that side, but want to file it away for future reference. Haven't heard about that one before.

[mason79]

thanks, yeah there is alot to learn about these things

[skids]

I believe that is the one that shot across the garage floor when I ran the bike with the alternator cover and electrics removed. Glug, Glug, "Now where did that damn thing disappear to?!"

Originally posted by laxdad
Got it. Thanks guys. No leaks on that side, but want to file it away for future reference. Haven't heard about that one before.

[Snow]

TC...destructive? Me? I don't know what you are talking about!