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Weird oil leak - 12 R1200RT

AjaxTheDog

New member
Checked the sight glass today and noticed there was lots of oily dirt stuck all over and around it. On closer inspection it looks like the oil is leaking from around the sight glass. I am used to seeing leaking seals around moving parts, but this one is just a plug in the block. I know it wasn?t leaking before so it just started around 8500 miles on my ?12 R1200RT. Time for a warranty repair.

IMG_7246.jpg
 
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That's a seep, not a leak. The sight glass has been an issue from day one with BMW. You don't say where you're from or where you're riding but if it's in and out of the mountains, there's a potential for the sight glass to 'try' to blow itself out' on the newer RT. This used to be such an issue, that I still carry a spare sight glass with me.

Here's a link to some info on it.
http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=461186

If you do a search for "r1100rs sight glass blow out" you see a lot of them. Though the search is for the earlier models and relates to the sight glass blowing out - yours can't - it does still reflect the problem you're having. Generally on startup, especially in higher altitudes [warm days, cool nights], the sight glass can cool to the point it contracts just enough that on cold startup, it moves a little [with the Hexheads] or blows out [on the older Type 259 engines].

During design of the Hexhead, BMW fixed the blow out problem by adding a circlip to hold the sight glass in. Now, if you experience the problem, it shows up as a seep like on your bike - which is FAR better than the sight glass blowing out and stranding you if you don't have a replacement and the tools to put it in on the road.

My knowledge with this issue on the Hexhead is, once replaced, the problem is over forever.

Here's another short bit about it:
http://micapeak.com/bmw/gs/gs_tel2.html#sightglass
 
Warranty,YES:)

You still inside warranty, this is a yes fix. I've seen too many already at my dealer on new Hex's that have had this fixed free:). It should be DRY all the time, no seap like in your pic. Randy
 
Yup shouldn't seep. Get it fixed. The circlip on hexheads positively prevents a catatrophic blowout as used to be fairly common on oilheads- folks used to carry plumbing bits to do a roadside fix on those or even a spare sight glass, too. But on a hex, the worse you'll get is an annoying seep.
 
Ohh!

That's a seep, not a leak. The sight glass has been an issue from day one with BMW. You don't say where you're from or where you're riding but if it's in and out of the mountains, there's a potential for the sight glass to 'try' to blow itself out' on the newer RT. This used to be such an issue, that I still carry a spare sight glass with me.

Here's a link to some info on it.
http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=461186

If you do a search for "r1100rs sight glass blow out" you see a lot of them. Though the search is for the earlier models and relates to the sight glass blowing out - yours can't - it does still reflect the problem you're having. Generally on startup, especially in higher altitudes [warm days, cool nights], the sight glass can cool to the point it contracts just enough that on cold startup, it moves a little [with the Hexheads] or blows out [on the older Type 259 engines].

During design of the Hexhead, BMW fixed the blow out problem by adding a circlip to hold the sight glass in. Now, if you experience the problem, it shows up as a seep like on your bike - which is FAR better than the sight glass blowing out and stranding you if you don't have a replacement and the tools to put it in on the road.

My knowledge with this issue on the Hexhead is, once replaced, the problem is over forever.

Here's another short bit about it:
http://micapeak.com/bmw/gs/gs_tel2.html#sightglass

Ohhhh!!!! A seep not a leak, I feel a lot better now :) . Thanks for the laugh. Mine does have the expanding ring so I guess it won't blow out all the way.

I wonder why they didn't just use an internal retaining ring and an O ring to keep this in and sealed. The expanding wire ring that is in there looks pretty cheesy.

Apologies for the lack of the profile info, I am just getting this all set up...
 
Ohhhh!!!! A seep not a leak, I feel a lot better now :) . Thanks for the laugh.

There's a REASON you need to understand the difference in a leak and a seep, wise guy. If it's a seep, you're not going to put oil all over the bike, road and tires and you're not "losing" oil, which you would with a leak.

If you don't want accurate answers, I suggest you don't waste our time to help you. I know I won't again.
 
Play well:)

I know I have been the kind of redneck wrench in my life to take this glass out and try to fix it, LOL. No really. BMW should step up indeed. I suppose in my above ways, I would take the ring out and silicone the thing, at least a temp fix:) and it may even stop the ugliness around that window. You may have BMW Dealer nearby, your first resource and the job is so quick, they should have NO issues with this work in and out, no app't...OR, buy the part, put it in yourself. I did not pay attention to your year bike/warranty? I had a earlier R1100GS and could not imagine the window popping out, as many have had happen! NOW that would be ugly:(...Good luck, Randy
 
The sight glass is in a slightly ribbed rubber surround. It is installed clean and dry in a cleaned and dried recess in the engine case. I drive them into place with an appropriately sized socket as a driver that rests only on the rubber but is slightly smaller than the ID of the recess.

When new, the rubber is nice and flexible. As the engine case heats up and and cools down the recess in the block expands and contracts and the flexible rubber does too, remaining tight. But after many heat cycles and the passage of time the rubber loses its flexibility. It then starts to seep. Now you have oil between the rubber and the metal engine case. Oil, doing what oil does, lubricates things and on the original design the engine could spit the thing right out of the hole. With the circlip on the later models this won't happen but it will still seep.

I replace them at the first sign of any oil around the sight glass.
 
Sounds easy:)

Paul G. makes this sound easy, so it likely is:). Guess all of them are not created equal, as my GSA 1200 has almost 100000m with no glass seeping at all. Some do, some don't I guess and ALL probably do with age and a LOT of miles. Anyhow, looks like an easy job to do. I HAVE leaks today, not sight glass but my Ohlin's, both of them at "one year" old:(. Already shipped them to NC, overnight to rebuild them at Ohlin's USA! Wish I had such a simple sight glass fix here:). Don't feel too bad there, my GSA sits atop my cycle lift table in pieces right now. Unexpected, just before a large road tour. Randy
 
All kidding aside...

Called the dealer and they have the part so I am scheduled to get my "seep" issue fixed.

I looked at the A&S parts fiche for this and there was a little PDF file from the shop manual by the part number that shows them using a special tool to cut out the old glass/rubber and install the new glass/rubber. A little more involved than I would have expected, so thank goodness for warranties!
 
Called the dealer and they have the part so I am scheduled to get my "seep" issue fixed.

I looked at the A&S parts fiche for this and there was a little PDF file from the shop manual by the part number that shows them using a special tool to cut out the old glass/rubber and install the new glass/rubber. A little more involved than I would have expected, so thank goodness for warranties!

Once they are oily they are easy to remove. I melt a hole in the plastic lens with a soldering iron tip and pry the whole assemblty out with a screwdriver. This usually eliminates any shatter or shards of the plastic.

Some folks use a sheet metal screw throught the lens and also through the perforated metal backer but I never found this necessary.

And as noted above, there seems to be a tolerance in the bore of the recess for the sight glass. Voni's very early R1100RS built in February '93 has a recess large enough that I can push the new sight glass in with thumb pressure only. My R1150R requires a driver to drive the sight glass into place.

We have had several K75s that use the same sight glass - they have all been all snug enough to need a driver.

As an aside, after the R1100RS spit one out I used an adhesive - Loctite Black Max which is a black rubberized super glue - to retain the assembly in place. But I don't put it on the edge, I put in on the back of the rubber to bond to the shoulder in the recess.
 
One comment..

Steve - as you mentioned, the R1200 series engines hold the sight glass in with a snap ring. There is no way it is blowing out like the R11xx engines used to. It might seep (mine never has) - but in this case given the age of the bike I'd suspect a defective seal or a flawed installation at the factory. Whatever - a new one should fix it right up.
 
Repair is done under warranty, but not all was covered

Last word from me on this: I had the repair done today, but I had to pay for the replacement oil necessary to perform the repair. That seemed odd to me as they had never asked for this before on other warranty repairs.

I started a new thread under the Motorrad area of the forum if you are interested in the rest of the story on this...
 
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