I have a 1983R80ST which has the same rear drive as the G/S. Mileage is 175K. My brake cam started to leak at 75K miles so I changed the o-rings. Leaked again at 100K miles and then the interval of the leaking just got shorter. This was a real problen because I have been in Central and S. America since October and half the time I didnt have a rear brake cause it was slimed with oil. I periodicially cleaned the drum and shoes with gas, changed the orings(not so easy to find sometimes) and kept riding. Now I am looking at changing the 2 bushing system I have for the tube system and hope it can be done.
As the bushings and the cam wear, it is impossible to keep the o-ring from wearing out very quickly. At least the oily brake shoes can be easily cleaned. This suprised me but I did it at least 6 times. Maybe the final word hasnt been written yet on this subject. Bill.
Since I wrote this message I have had the course on the bastard o-rings. I rode to Calgary headed for Alaska and had
Bob,s BMW in Jessup, MD ship up two bushings and the tube listed as the correct part numbers for my machine. When they arrived they were not correct as they were too small in OD/ID. I will post the incorrect part numbers I was sent as soon as I can find them. The bushings came from Germany.
I had a stainless steel tube machined to fit my rear drive and brake cam to finially solve the problem. It took some doing but I got it installed correctly and finially no leaks. A $90 Canadian turned into a $450 job and I was bummed. I will not name the shop I used but be careful in Calgary with repairs. If you have leaks fix it right or pay the price I did. Make it a winter project and rebuild the rear drive at the same time and be done with it. Find someone with experience, tools, measuring equipment and parts to get it done right.
I can recommend Anderwerks in Calgary. Dave knows the bike and has parts. I also recommend this man. He is a great machinist and rides a BMW. In Calgary,
Neils Machine Shop
Stainless steel Neil
Tel no.403 275 8098
[This message has been edited by Bill Shockley (edited 29 June 2005).]
[This message has been edited by Bill Shockley (edited 11 August 2005).]