The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: ThomasH on December 15, 2008, 11:13:29 PM
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Hello Folks,
Can you help me identify what seal I need?
On my 1982 BMW R65ls, I recently had the rear drum brakes worked on, that is to say replaced, and the mechanic also said my 'rear wheel bearing' was spinning in its mounting.
He said he replaced the rear wheel bearing and the rear brake shoes, and the rear brake seemed to work fine for a few hundred miles.
Then the other day, I noticed the rear brake was "doing nothing", by which I mean that when I pressed the rear brake pedal, they rear brakes did not slow the motorcycle down.
As it was dark, my first attempt to resolve the problem was to reach down and turn the 'wing nut' on the rear brake rod, thinking maybe it needed a bit of tightening/adjustment.
But I noticed the wing nut was slippery! Uht-oh! :-(
Sure enough, when it was light enough to see, I noticed a black ring around the rear brake drum and other indications of some kind of lubricant leak from inside the rear drum. (Like more black staining around the axle and around the place where the brake lever goes through the drum.)
Can you folks advise me as to which seal(s) has most likely gone bad? I see there is an online parts fiche at:
http://www.maxbmwmotorcycles.com/fiche/MainDiagrams.asp?mospid=47853
Perhaps you can even give me the part number(s) I should order?
Back when I had more time, I recall changing all the rear shaft fluids, so I am hoping this will be a straightforward replacement. Any hints or advice would be greatly appreciated!
- Thomas Haller
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The O-rings on the rear brake cam rod are often the cause of what you are experiencing.
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I'll second Justin. When a similar problem occurred on my machine, I worried it was a seal somewhere in the rear, but eventually discovered the problem stemmed from the O-rings on the brake cam lever. My leak resulted from the inside ring. Once I changed them both, the leak switched to the outside and onto the brake cam lever. Slipping on an O-ring can be tricky and I figured I must have the rolled the one on the outside, so I replaced it again and the problem was solved inside and out. So glad I didn't have to bother with the seal.
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Thank you Frank and Justin!
I will look for these rear brake cam rod o-rings first then...
I will keep you informed! ;)
- Thomas
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Very much agree. Them O rings get a bit compressed with age too. About 1,000 miles after changing the internal oil seals cos they had definately been leaking, I changed mine but a little oil was still escaping onto the brake shoes >:( (). I decided to cut a third groove into the spindle, slightly less deep than the original grooves making a tighter fit for an extra the third O ring which I squeezed on. No oily problems for 5,000 miles since. Just thought I'd mention that in case your first O ring change doesn't do the trick.
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These are O-rings
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi402.photobucket.com%2Falbums%2Fpp101%2Fralescuba%2FP9060278mala.jpg%3Ft%3D1229638491&hash=e46072ec342ed44158bf9bc33a3b0ac73018cf8b)
and they are fitted inside this
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi402.photobucket.com%2Falbums%2Fpp101%2Fralescuba%2FP9060271mala.jpg%3Ft%3D1229638589&hash=aa1cfa4e63b64451e34e1917b78925165503195f)
obsreve the hole with bronze lining at the right hand side of the hub (partialy covered )
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Make sure you get enough. I guess some models used more seals. I bought 4 for mine and only had spots for 2, so I'm set for next time I guess. Yeah I labeled the package the spares are in. :-)
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Make sure you get enough. I guess some models used more seals. I bought 4 for mine and only had spots for 2, so I'm set for next time I guess. Yeah I labeled the package the spares are in. :-)
I have read of some folks having theirs modified for a third o-ring.