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Oil Weeping from fill hole?...argh


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I have an 04 1150RT that has a bit of oil weeping out of the fill hole...at least that's how it appears. I've put a new o-ring on the cap, but it's still seeping. Any suggestions?



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Check with realoem.com, there are 2 orings there, one on the cap and one on the thing that the cap screws to ;)


Replace both of them and be done with it ;)



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This is an all-too common experience. There are two o-rings in the assembly, the one on the cap and another between the plastic insert and the valve cover. Both need to be replaced and both should be fitted dry.


There is at least one aftermarket filler assembly that fixes more positively to the cover useing grub screws. Linky



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Bo, my '04 RT had the same issue until I started to always wipe dry after removing, the o-ring on the filler cap.


Might work for ya,



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Thanks guys. Will replace second o-ring and wipe them both down. If that doesn't work, will go with the aftermarket job.


It will work. Take your time and don't damage the valve cover popping out the plastic insert.


If you are really concerned, a replacement plastic insert can be purchased with the two O rings as a kit from BMW for not much $.


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Thanks. I'm thinking about putting in the "Viton" o rings on the cap and the filler tube. Does anyone know what size(s) I'm looking for?



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I had the very same problem on my 2004 1150RT. I was on a trip 5 years ago from Florida to Baltimore to meet a friend for a ride down the BRP.


I noticed some oil on my left pant leg and saw it was coming from the oil filler cap. I made a detour to the local BMW dealer in Virginia, just south of DC.


When I told the parts guy at the dealership about the leak he said that I should replace the insert, the cap and both o-rings.


I was a little concerned about cost what with the price of all things BMW. But I was pleasantly surprised when the parts guy rang up my invoice and the amount was under $20.


So I said something to the effect that those parts were very cheap. He said "yeah, that's why they leak!"


Sure enough, it leaked again for the rest of the trip.





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Use some brake clean or throttle body cleaner to clean the o-ring, plastic insert and the cap.



I use 92% isopropyl alcohol, which tends to swell rubber (if only temporarily). Being a cheap bastard, I cut a thin spacer out of some gasket material, and slipped it between the cap and O-ring in order to generate a little more pressure on the seal.

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Brooks that's funny.


I ran by the dealer today, got the lower o-ring and new filler cap...problem solved. I just ran it like a scalded dog and no oil on my aerostich...


Thanks for all the help everyone...now on to the next thing to tinker with...

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