Brake caliper cleaning

[Jninja]

I have a 06 636 that I am having issues with brake dust buildup causing the pistons in the calipers to stick. The Kawi factory service book says to use ethyl alcohol or brake fluid to clean the calipers. I used brake fluid and a tooth brush and lightly cleaned them and they released but where still very grungy. My bike only has about 3k miles so I don't want to rebuild the calipers yet so my question is, is there anything specific I can use that will get the brake and track grunge out of my calipers without damaging the seals in the calipers?

[Jim McKenzie]

You are going about it in the right way, but unfortunately there isn’t any quick or easy way of cleaning the calipers once they start sticking.

To properly clean them, they will have to be dis-assembled completely. Using a toothbrush and fine Scotch-Brite, rub-a-dub all of the pieces using either of the fluids that you mentioned above. If you use the ethyl alcohol to clean them, soak all of the moving parts and seals in clean brake fluid prior to re-assembly. Be sure to torque the fasteners properly on re-assembly.

One note on torque values…all printed torque values (unless otherwise stated) are for dry fasteners. Since no fastener should ever be assembled dry, be sure to DECREASE the printed torque value by 18 ~ 25%, depending on the lube.

[Jninja]

Sounds good, thank you for the help.

[Jninja]

Well the caliper rebuild went fairly smooth, not too difficult other than trying to get the pistons out. Everything is reinstalled and the brakes have been bled completely, they have excellent stopping power but I am concerned about the master cylinder. This is my first expierence with a brembo master cylinder, it seems a little mushy when you apply the brakes. It stops great but is this a characteristic of the brembo to be a little more mushy than the stock master cylinder? If it is than I'm good, if not any suggestions would be greatly appreciated!

[Jim McKenzie]

I am not fond of assuming things, but, assuming that your Brembo master cylinder is working properly (not in need of a rebuild itself), and is the correct size for your application, it sounds like you might still have a little bit of air in the system.

All else being equal, a Brembo master cylinder should not be "mushier" (that is a real word by-the-way, I checked) than your stock master cylinder, at least in my experience.

[Jninja]

Thats what I was thinking myself, my only problem was not having another brembo to check to see. I will definently bleed it again and see how much better it gets, I appreciate the help sir.