Join Date: Mar 2007
Location: Nottingham Township, PA, USA
Input shaft sealing ring
A week ago I noticed a change in the grip pressure with the clutch on my 2004 K12RS. I checked the clutch fluid level and found it a bit low. I got the bike home without incident and it has been parked since then. I went through the effort to get to the slave cylinder (oh, how I miss some of my other bikes). The slave cylinder was wet and so was the cavity in the gearbox housing. I pulled out the pushrod and it had just a little bit of fluid on it. I cleaned everything up and ordered a new slave cylinder, gasket, and banjo bolt washers. While waiting for the parts to arrive, I changed the engine oil and cleaned up the bottom of the engine, etc. I checked in the slave cylinder cavity last night and I found a small amount of fluid. I shoved a paper towel in the cavity to dry things up. I checked again tonight and found a small amount of fluid again.
I didn't lose a lot of brake fluid, maybe about an ounce, so I am not too worried about the clutch being contaminated. I wasn't experiencing any performance issues with the clutch. I am concerned that the input shaft sealing ring (I think that's what it's called) may be compromised and is leaking fluid from the gearbox. Is this possible? The bike is on it's centerstand and would the gearbox fluid even be as high as the sealing ring is positioned on the gearbox?
If it is recommended to replace this sealing ring, is there a good procedure, outside of the what is in the service manual, for doing so? I don't want to purchase BMW's outrageously priced tools. Any suggestions or comments would be greatly welcomed.