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Oil Leak Help

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Brodo.Waggins

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R18 TC
Hi Everyone, I've got an oil leak and wondering if anyone's encountered this issue? Another person on the R18 FB group had the exact leak and dealer said it was rear main seal leak. My bike just ran out of warranty so I'm wondering if anyone can provide any guidance.

Bike is a '22 transcontinental with about 4800 miles.

Edit: attached additional pic, seems to be leaking from air intake tube.
 

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That looks like a strange place for a main seal leak. I am thinking it may be coming from the airbox from oil collecting there from the crankcase vent. If you have overfilled the crankcase perhaps excess oil was pushed into the airbox. Just a thought. It would not be too difficult to remove the air filter and look inside for oil collecting there.
 
Judging by the first pick, I would say transmission breather (I have a hard time figuring out where I am at in the second) ... a little too much oil in the gearbox and/or the oil 'foamed' a bit and it drooled out through the transmission breather.
I had replaced mine ... the part is not very expensive ... but it is a pain in the @$$ to change that little thing. What I would do ... (that is me and what I did) ... drain the oil from the gearbox, refill with with just over (or at) 1 liter (specs call for 1.15l) ... and be aware of the oil you are using ... some work better than others Gearbox Oil Thread ... have a look here if you need ideas, but don't use the Schaeffer oil ... after running it for a while I switched to Bel-Ray.
Then wash the oil off the outside and see if the problem returns before diving into things like the main seal or such.
But that is just my 2¢ ;)
 
I wouldn't discount Ulrich's advice, as components are close together on the R18's. However, I know that the oil breather tube routes into the airbox and, that over time, it will accumulate with oil if the drain hose hasn't been opened up in a while.

So, before trying Ulrich's idea, check this on your bike first:

Airbox drain plug bottom view.jpeg

Specifically, this is the endpoint of part # 14 on this microfitche:

BMW Airbox.jpeg

Let us know how it works out for you.

Mike
 
My transmission breather leaked and the dealer said it had small tear. I have no idea how it could tear, but that’s what they said. They replaced, it all good now. When it leaked, it leaked straight down and there was a bunch of foil on the bottom of the bike, not over the side like that.
 
I wouldn't discount Ulrich's advice, as components are close together on the R18's. However, I know that the oil breather tube routes into the airbox and, that over time, it will accumulate with oil if the drain hose hasn't been opened up in a while.

So, before trying Ulrich's idea, check this on your bike first:

View attachment 20503

Specifically, this is the endpoint of part # 14 on this microfitche:

View attachment 20504

Let us know how it works out for you.

Mike
Right! ... I forgot all about that tube that goes to the airbox !!!
 
The first time I removed the airbox plug on my R1200C, I thought the crankcase was draining. It was a used bike that somehow gathered oil.
I have also over filled the tranny only to find out it pukes out the top and runs down the side.
 
I wouldn't discount Ulrich's advice, as components are close together on the R18's. However, I know that the oil breather tube routes into the airbox and, that over time, it will accumulate with oil if the drain hose hasn't been opened up in a while.

So, before trying Ulrich's idea, check this on your bike first:

View attachment 20503

Specifically, this is the endpoint of part # 14 on this microfitche:

View attachment 20504

Let us know how it works out for you.

Mike
Attached is a video, maybe it will help:

 
I drained a little bit of the oil and it's fine now!
Yup ... in my experience (done it myself) even a little too much will do exactly do that ... a bit low will absolutely not hurt anything ... IMO ... and nice going! Saved yourself a big 'can-of-worms' trying to change that little breather ... trust me I did it ... not much fun at all!!
 
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