Brake problems on a KZ900

I wound up just rebuilding the caliper for the time being. My bike is my "daily driver" so I wanted to get it back on the road ASAP. I didn't have any grease (long story) so I had to make 10W-30 work

I am looking into a dual disc kit, in which case I'll make sure everything is properly rebuilt with new seals and such.

Plummen: Thanks for the cleaning/plating tip. I will be sure to do things that way next time around. (Hopefully by then I'll have another bike to ride while I'm working on this one )

Polar_Bus: Actually, there was very little corrosion in the bore or on the piston. Just a bunch of dirt/dust/crap built up that was easily wiped off with a rag.

TomW: Thanks for the brake fluid clarification! The main reason I am considering the switch to DOT 5 is the huge decrease in paint corrosion from the silicone-based fluid. Now, my bike is FAR from a show bike, so nothing is definite; but if I did make the switch, I would make sure EVERYTHING is new (if possible) and wiped down; MC rebuild, caliper rebuild, new SS brake hoses, etc..