Brake Caliper Rebuild

Anybody know just how clean the piston and cylinder have to be to be still usable? Here's some pics of where they are at now. It's off a 76 KZ750 twin in case that matters.

That piston is junk. Get a new one.

The caliper has some pretty deep corrosion. I'd try scraping out the groove with a plastic/wood scraper, followed by scrubbing with scotchbrite. A stainless steel brush on a dremel would be a good option if you have one. Can't tell for sure but if the pitting is too deep you may have to look for some new calipers. Oh, and make sure to use OEM Kawasaki seals. K&L brand caliper seals are JUNK. Very hit and miss. I've been burned before and wouldn't use them unless you have no choice.

Thanks Nessism. I feared that would be the response. The good news is that it is the rear brake which is really only there to give your right foot something to do right?

Now to try and find 40 year old caliper bits that are not in even worse shape.

Post up a pic of the whole caliper, if I have one it's your's for shipping cost.

Same for if you just need a piston

Here ya go. Much appreciated.

Just home, I'll see what the inside looks like tomorrow

The actual caliper looks like the same one used on the front of many Kawasaki's from 1978-1980 so it should be easy enough to find something in working order.

I believe the piston sizes are different between the fronts and the rear, not certain tho, I swapped mine out.

Piston wiped off one little rust spot on main body, pin head sized, one rust spost at bottom (not near where the seal would be) and looks like plier marks at the top. caliper bore should be good but has old dry brake fluid in it. Let me know

Sent you a PM