Explanation About the $ 2000. O-Ring

[b25bsaboy]

It can be done, but it is difficult and you may not feel confident that you got the $2,000 "O" ring back in correctly if you have to slide the cooler back across the filter. Easier just to drop the exhaust and lube the exhaust nuts at the same time. It also saves you having to take the lowers off too.

Good morning!

I came across this statement in an earlier comment, read it and started thinking about it, as I just change my oil on my 1989 R100RT. Getting at it was a bit awkward without taking the exhaust pipes off, but it is much easier if the machine is up on a lift and your able to look right at cover plate to get at the 10mm bolts that hold the oil frame to the engine case.
I replaced the black rubber smaller one with a new o-ring, but did not renew the larger white in color larger one, as it appeared to be fine with no nicks and was not starting to get hard.
My question is which of the two are the ones that you have to be careful with and what are the tell tale signs that you may have an issue after you have reassembled the oil filter housing along with the junction oil cooler lines.

Came across this note in which Kurt responded to a question on an earlier Airhead Oil Line question. Thank you Kurt:
http://www.largiader.com/tech/filters/canister.html
Will be ordering some new white Orin's for future oil changes.....

 

[20774]

I don't have any experience with an oil-cooler equipped bike, but I would assume that all o-rings, even the black one is important. But the large white o-ring is probably the most important part of the whole setup. It does two things - it seals oil from getting to the outside of the engine and also seals oil from leaking back into the sump without going through the filter. This latter part contributes to the expensive side of the $2000 - lack of filtering and eventual drop/loss of oil pressure.

If your white o-ring doesn't look squareish after a full stint of use, then you're on the verge of the second problem. When the cover goes on, it needs to squeeze the o-ring to about 75% of its original diameter. That squeezing process is controlled by the metal shims that are placed inside the oil canister first and, if necessary, a gasket on the cover.

All of this is discussed on Anton's site and most likely on Snowbum's site.

 

[wecm31]

When the cover goes on, it needs to squeeze the o-ring to about 25% of its original diameter.

Kurt, forgive me for jumping in....but I think you meant to say the oring is squeezed enough to reduce its diameter by about 25%, meaning its 75% of the original size. Exactly as you describe; if the white oring is not noticeabley squarish in cross section after removal, you need to come to grips with the cannister depth per Anton and Snowbum.

For the record....I just followed the setup of the PO on my bike for nearly ten years, no shims/gaskets. Just the cover (no cooler). When I finally digested the issue from Anton's site, it lead me to start using two shims. Now I can feel the cover seat with the oring during assembly and the old one comes out a bit square. I was likely not doing the bike any favours without the shims, but still rolled over 85K miles without them.

 

[20774]

but I think you meant to say the oring is squeezed enough to reduce its diameter by about 25%, meaning its 75% of the original size.

Good catch...you're correct. I'll go back and edit my post.

 

[toooldtocare]

Mono-shock bikes have more room between the thermostat and exhaust pipes, much easier to change the filter. I never removed the exhaust on my mono-shock bikes, but I once did mess up the O ring. No damage because oil came out of the fitting because I never use a gasket. If there had been one I would not have noticed until damage was done. That O ring was pinched between the canister and cover because it became dislodged as I slid the thermostat across.

 

[Stan_R80/7]

Not to in any way dissuade paranoia about the oil change cover cap o-ring: but my '78 does not have an oil cooler, uses the straight oil filter, and the most trouble with it is getting the cover past the frame. No doubt, if the o-ring were not back in place it would likely leak and the filter would not work properly.

After a 14 year hiatus, taking mine back off and replacing the oil filter (A BMW# 11421337198) reveals it is possible to screw up that o-ring - but only for the mechanically challenged. Those who are (such folks) generally know themselves. Sometimes extra scrutiny on such a topic does not help. Maybe the RT and RS fairing folks with an oil cooler have more reason for concern?

 

[donbmw]

I still think this $2000 oring deal is make and big deal out of nothing. I have had my R65 since new and have always installed the oil filter, shim, oring gasket and cover the way it first came off. Shim, oring gasket and cover. I have never check the depth of the canister. Have reused the oring many times. I have close to 100,000 miles on this bike. Never heard of the high price oring this fourm came out. Have been a MOA member for almost 30 years cannot remember reading and thing in the ON about this until the internet brought this up. As long as the filter is installed the correct way you are not going to have a problem. I have a friend that changed his oil the day before we were to leave for a week. We luckly got only a little ways down his road and the oil light came on. He had a R100Rt had not watch for shim and oring when removing the oil cooler thermoster and put it back on with out the shim. Installed everything back like it should had no more problems. I think is all get down to at least have shim and oring and maybe gasket before installed what ever covers the filter.

 

[lkchris]

Of course it's the thermostat and NOT the cooler that's being slid.

It's a lot easier to do with the hoses disconnected.

And, most of the monoshock bikes will also have the folded-over edge to the interior canister where BMW's design intention is that no shim is required. This thing, BTW, was never designed as a shim, i.e. something to take up a calibrated amount of space, but rather simply as a device to protect the o-ring from the sharp-edge of the earlier canisters and, obviously, give it something to seal against.

I'm another that thinks most of this is much todo about nothing. One wonders if it's not a self-fulfilling prophecy thing, that is if you squeeze the o-ring enough you may indeed move the canister. Have never had a problem with this in 30 years, although did pinch the o-ring once. It fairly immediately leaked. Lots of what our "gurus" preach reminds me of Pres Ford saving me from swine flu.

 

[20774]

I still think this $2000 oring deal is make and big deal out of nothing. I have had my R65 since new and have always installed the oil filter, shim, oring gasket and cover the way it first came off. Shim, oring gasket and cover. I have never check the depth of the canister. Have reused the oring many times.

I had my /7 for probably 20 years and did exactly as you say...I had changed oils many times and had just replaced the filter. I remember seeing the white o-ring early on, even pulled it out and said WTF. Didn't have another one, so just put the old one back in. Then I'd heard about the canister depth issues, etc. Since then I've been replacing all the parts each time...have even added the cover gasket in order to optimize the o-ring compression.

While "if it ain't broke, don't fix it" might be a decent approach, my concern would be the continuous use of the large o-ring, allowing it to become brittle and lose its elasticity. Eventually I suspect it will fail and could lead to an oiling problem.

But in the interest of complete protection for the "blood" of the engine, I think it wise to understand the situation and do the best you can. That's how I roll!! And YMMV...

 

[AntonLargiader]

From what I've seen, the early bikes are generally not subject to canister recession. Most of them don't have enough canister depth, actually. The later rolled-edge canisters are too short, and can recede into the case.

However, I just read a case on the Airlist where a 1980 canister (presumably a sharp-edged one) was 4.44mm. Oil systems have started to leak at smaller depths than that. So yes, it's actually a real issue for some bikes.

 

[markst1]

correct size filter

Last year I did an oil change on a new to me '88R100RS. On disassembly, I realized that the last person to change the filter used the wrong filter (way too short). The white O ring and associated parts looked fine. The O ring was appropriately compressed. So the oil must have been bypassing the filter. But the bike had been running fine like this with no apparent oil pressure problems. My question is: How does the bypass of the white O ring lead to problems, while lack of seal of the filter itself (bypass of the square black O ring) is not a catastrophic problem? Does a bypass of the white O ring vent the oil pressure directly to the sump whereas bypass of the square black O ring does not?
Thanks
Theo Marks
'74 R75/6
'88 R100RS

 

[ISAMEMON]

canister recession

just thinking, is this a ongoing problem, like valve seat recession. is this something you need to recheck on occasion on your own bike ?
Ill check a bike that is new to me for service, or a bike new to me, but I dont constantly check it.

Like I said, Ill check it the first time, compare measurements, figure out what I need to use, but in the past few years I have not rechecked it on my bike
use BMW filters, o-rings etc, not aftermarket stuff, so is anything gonna change ??

 

[20774]

My question is: How does the bypass of the white O ring lead to problems, while lack of seal of the filter itself (bypass of the square black O ring) is not a catastrophic problem? Does a bypass of the white O ring vent the oil pressure directly to the sump whereas bypass of the square black O ring does not?

Theo -

You're correct in your assmptions. Not going through the filter (in your case) is only really bad if you had severely dirty oil. But if the o-ring doesn't seal, that will let oil back to the sump, and in a severe situation, you would not develop any oil pressure. The white o-ring does all the sealing in the area to create the sealed volume in the canister area. It seals against the cover to keep oil from leaking to the outside. It seals to the shim and the canister side to keep the oil from bypassing into the sump.

 

[20774]

is this something you need to recheck on occasion on your own bike ?

I'm like you...I checked it once 5-6 years ago...haven't checked it again. But it probably pays to glance at the canister-case relationship each time. Plus, if the o-ring doesn't look the same each time you change the filter, than something's changing. If I saw that, then I'd probably remeasure and reassess.

 

[roncooper]

I just helped a friend change the filter in a new to him 85 R80. The filter was an old non hinged one and the shim was on the outside of the white O ring.

The O ring was compressed and had a minor cut.
We measured the depth and came up with 3.5mm. We put it back together with a hinged filter, new O ring, cover gasket and shim(inside of the O ring.)

 

[AntonLargiader]

How does the bypass of the white O ring lead to problems, while lack of seal of the filter itself (bypass of the square black O ring) is not a catastrophic problem?

The filter doesn't hold any pressure; it just sits in a pressurized environment. Whether the oil flows through it or around it, not much difference except for the filtration.

You can take the filter out completely and the pressure will still be there, just like a typical household water filter setup.

 

[73043]

I measured and figured I needed 2 shims. Now I??m changing oil&filter, o-ring is round. So I figure I??ll ad a shim. Can??t find it anywhere, the parts nr. on it.
Hans

 

[20774]

We measured the depth and came up with 3.5mm. We put it back together with a hinged filter, new O ring, cover gasket and shim(inside of the O ring.)

I probably would have not used the gasket. All the gasket does is to move the cover farther away from the white o-ring, lessening the compression. On my /7, the canister depth is less than 3mm, so I need the gasket to move the cover away. Anton has done all the math here:

http://www.largiader.com/tech/filters/canister.html

 

[20774]

I measured and figured I needed 2 shims. Now I??m changing oil&filter, o-ring is round. So I figure I??ll ad a shim. Can??t find it anywhere, the parts nr. on it.
Hans

RealOEM has the breakdown:

http://www.realoem.com/bmw/showparts.do?model=0333&mospid=51642&btnr=11_1721&hg=11&fg=42

The shim is the washer.

 

[73043]

Thanks Kurt!
Hans