Hey all, I took the rear wheel off my 09 CBR600RR and reinstalled it and tried pressing down rear brake pedal and nothing, just goes all the way down with no pressure. Brake caliper seems seized. Any help is greatly appreciated!
I did and nothing. There’s absolutely no hydraulic pressure to the rear brake pedal, just the spring giving any resistance. I managed to pull the brake caliper piston out a little bit absolutely will not recess back in.
If the caliper were seized but the system was otherwise fine, you'd still be able to feel brake pressure though, yeah? The caliper would either be stuck closed and cause dragging brake, or stuck open and not fully or at all engaging, but because its stuck, you'd feel that as resistance when you push the pedal. I'd guess that either (more likely) there's still an air bubble hiding somewhere within the system or (less likely) you've got some kind of issue with the master.
Capt Obvious asks if the piston is stuck then he would guess the fluid has turned gooey and caused the issue? So the point is eliminate the variables first then post your question here.
Update: I used a heavy duty clamp to force the piston back in and heard a pop, then voila, it started working again, brake pedal had hydraulic pressure and all is right with the world.
How long since the last service of the rear brake system? I know a lot times rear brakes aren't serviced as often as the fronts. From your description and fix, I'd say its time for a full tear down and rebuild. I'd bet that there is a lot of gelatinous brake fluid in there.
I just flushed the system, so it had fresh fluid in it. But the bike did sit for a couple to few years in the prior owner’s garage. So I’ll plan on new seals in the caliper as well the master cylinder.
Flushing it wont get it. I've rebuilt quite a few sets lately. Even after being flushed, disassembly showed there was still gelled up fluid, hard deposits, etc, still in there. I was surprised that the brakes were even still working.
