Rear brake o-rings

[hzbloke]

I was chasing a leak in the rear drive of my '86 R65 (it turns out it may have just been a weeping fill-level plug) and so ordered the various seals/gaskets/o-rings. The o-rings on the rear brake cam (21) were standard looking ones that fit in a groove. The ones that were sent are very thin and larger diameter. Looking at the fiche I came across this (item 20):



There are two item 20s listed.

20 O-ring 10X2 2 07119906328 $0.13
20 Gasket ring 12X1 2 35211457605 $1.32

The o-rings on the shaft (21) were definitely the 10x2 and there were no others. Does anyone know anything about the 12x1 'gasket rings' . Are they an alternative to the o-rings or should they all be fitted and, if so, where? Motobins only list the 12x1 as being for my bike.

Cheers
Ray

[montmil]

Both my 1981 and 1983 R65s have a felt "gasket ring" which is most likely the 12x1 item.

BMW mothership expects the felt to absorb the final drive lube that always seems to find a way out.

[Ray from Indiana]

Harbor freight sell a box of o-ring assortment made of nitril rubber. Part of that assortment is 10qty 9.8 x 2.4 rings. You can make them fit

Leaks there usually caused by overfilling

[hzbloke]

Number 18 in the diagram is the felt 'gasket ring' (19 is a washer). I have one on mine too, on the right-hand outside of the final drive under the brake lever. The o-ring that puzzles me is very thin (1mm) and the same diameter as the shaft (12mm).

I picked up some 10x2 o-rings from a local car parts shop. Thanks for the suggestion about the Harbor Freight assortment but their nearest store is a fair way from here.