Topic: front brake master cylinder Q's

[killersoundz]

The piston in the brake master cylinder I have doesn't appear to be going back in. I pulled the drain bolt out and trying to push it in it's not going anywhere. Looks a little rusty in there too when I took the brake pad out. It needs to go back in to be able to install it on the rotor. Probably needs a rebuild kit maybe eh? I do have a cleaner looking piston here

[MCRider]

point of order: the master cylinder is on the handlebar. Do you mean the piston in the caliper? At rotor level?

Everything mustbe clean and shiny to ensure function. Yes you should be able to push the piston (via the pad) into the caliper, if the bleeder is turned open or removed.

Not really a kit for the caliper. Disassemble, clean everything, replace the square section ORing (it does the lions work of retracting the piston).

rebuild kits available for the master cylinder.

[BeSeeingYou]

Spend the $6 for the new O ring.  You need to clean the seal groove too and check the condition of the piston.  Some small pitting is common and may not be a problem but at some point it becomes unusable.  How bad is bad....a picture would help.