Aftermarket 5/8" Rear Brake Master Cylinder

Instead of rebuilding my 77' KZ1000A frozen rear master cylinder, Has "anyone" used any aftermarket 5/8" rear master cylinders with the remote fluid reservoir that you see on ebay??? It's seems with a little fabrication they could work. The mounting holes ( 2" spacing ) appear to be the same as the original KZ master. I think the remote fluid reservoir could be mounted somewhere on the frame and the "stock" KZ brake pedal pushrod might be able to be used? Just a thought, and I'm sure someone on this forum has probably used these master cylinders.

If possible, best to stick to the original m/cyl setup - most parts are still available (except for the actual m/cyl and reservoir) I was able to "un-freeze" the rear M/Cyl on my '78 Z1-R which I think is identical to the one on '77 Z1000. I removed the circlip and stopper then got a suitable sized "ezy-out" (LH threaded tapered screw device) and carefully screwed this into the hollow part of the piston where the rod engages. I kept turning until the piston decided to let go. Replacement piston and hardware are available through Z1 Enterprises. Be careful not to damage the bore of the m/cyl or you'll be up for a new m/cyl or re-sleeve job. After I rebuilt and bled the rear brake system I found I had a seepage of fluid from where the reservoir and the m/cyl bdy meet. I had to replace an O-ring which sits on the inner circumference of the body of the m/cyl - this is not identified in the IPB but available from Jim at Redline Cycles in Skokie, ill. Hope this helps, Bill.

Weales, thanks for the advice. I did manage to remove the piston. Found a tap of similar I.D. of the rear hollow portion of the piston. Screwed tap in until it had a good bite. Then put opposite end of the tap in vise. And with block of wood and hammer, drove the master cylinder body off the piston assembly. A lot of crude, but cleaned well. Re-installed, seems to work freely with no leaks.

I have one off my 77 KZ1000a1 if you need it. Moves freely, no leaks, rebuilt it and took it off 6 months later when I changed to modern rear sets. PM me if you need it.