tmikeyb
XS650 Addict
I am still working on getting a nice working front brake. My new pistons were so tight in the caliper that I had to drive them in with a mallet. They would not release once they were installed on the bike. A member here told me this was too tight and that the pistons should not be that tight. I disassembled it again, and spent a lot of time scraping out the seal grooves. I dug a lot of rust specs out of the grooves. I cleaned the walls again. Then I rubbed the walls with 600 grit sandpaper and light oil. I finally got one side to the point where I could push the piston in with my hands. I worked on the other side for at least as long, but could still not push the piston in by hand (with the seals in place). I finally got it to where I could tap the piston in pretty easily with light taps from a mallet. Now it's all back on the bike. It is much better, but the brake still doesn't release completely. I have instant brake, with no play in the lever. Is this normal? Then the brake will back off only very slightly when the lever is released, just enough that I can push the bike with a good bit of force. The brake does not completely release. I have no experience with disk brakes, so I don't know if my piston{s} are still too tight, or if the master cylinder is somehow not releasing pressure as it should. I find no help in the manual. I'm not sure where to go from here. Any tips, advice, or info is much appreciated.