Replacing the rear brake rotor (part 1)
Wednesday, Nov 25, 2009
Ignore the missing muffler and rear shock. The shock is getting a needed re-build. While the bike is down, anyway, I’m going to finally replace the rear brake rotor. I’ve had the replacement parts sitting on my bench for a month or two.
The replacement rotor is from Beemer Boneyard. It is about 60% the cost of a new rotor from the dealer. A new rotor calls for new pads and mounting screws. Those came from the dealer.
I started out by removing the mud guard and the rear wheel. I used the scissor jack to support the swing arm since there is no shock to hold it up.
After popping the brake pin partially out I removed the caliper, the old pads, and took the caliper partially apart for a good cleaning. The portion still attached to the brake line was cleaned with spray on brake cleaner then cable tied out of the way.
The end of the screws were heated to release the thread locker and then broken loose from the one spot in the FD where you can reach them with a T-40 torx. Major WWWobble helped by actuating the clutch when it came time to rotate the rotor to position the next screw. After all screws and the old rotor were removed I chased the threads in the flange to clean out any old thread locker.
Something I do every time the rear wheel is off is check for cracks in the flange. It’s a known issue on at least some of the ’04 and ’05 GS models. Don’t know if it effects other models or years. I cleaned up the portion of the swing arm hidden by the tire and then the flange and took a look. Damn!
I don’t think I have the tools to pull the flange, so I’ll instead remove the FD from the bike and let the dealer do the work. It shouldn’t be that much labor. I suspect the part will be expensive, though. And they probably won’t have the part in stock.