Rear master cylinder compatibility 81 GPz550

I found out from searching around that they do no make a rear master cylinder rebuild kit for my specific year. Can a different year GPz cylinder be fitted onto the bike? The 82 model looks almost identical other that the pushrod going from the brake pedal to the cylinder. Perhaps switching pushrods?

Contact www.z1enterprises.com I understand they will put a kit together to replace the worn out parts for the master cylinder.

I was on the phone with them yesterday and they do not carry it, nor do any of their suppliers. It says in the kawasaki parts fiche that it is an "obsolete" or discontinued part. I'm at odds now as to what to do.

Redox6022 wrote: I found out from searching around that they do no make a rear master cylinder rebuild kit for my specific year. Can a different year GPz cylinder be fitted onto the bike? The 82 model looks almost identical other that the pushrod going from the brake pedal to the cylinder. Perhaps switching pushrods?

Any possibility of restoring the existing master cylinder to serviceable condition without using any new parts?

Sometimes the cruddiest looking cups may be cleaned and re-used, thereby eliminating the need for a replacement piston.

If the bore isn't too badly pitted, it may sometimes be smoothed to serviceable condition.

Good Fortune!

How would I go about doing that? Is there a way to fix the leak on the piston? How would you go about cleaning it? I've only ever replaced a master cylinder (the whole assembly), and that was on an old MG. I'd really appreciate any and all help you could give me

give tim a call and see if he has a master cylinder in his collection 402-944-6111

Does this guy Tim run a business or is it some random dude I call up and ask "hey man I got your number from a forum, you got parts lol?"

I m in the midst of this right now. I took off the whole back brake system completely. Master cylinder with reservoir, brake hose and caliper. I rebuilt both caliper and M/Cyl. Taking apart the cylinder was a bit..scary, but after it was apart and cleaned up, its not bad. I would do this first and possible, with cleaning up,it may not need rebuilding. Clean up the cylinder good and look inside to see if you can see any scoring. I took a piece of 800 grit wet/dry sand paper, rolled it up and inserted it in the cylinder and spun it around inside rather like a hone. Cleaned it up with brake cleaner and then looked for imperfections. Then clean up the piston with cleaner and soft bristled brush that will withstand brake cleaner without melting. After both are nice and clean, coat the piston with a bit of clean brake fluid and reassemble.

I looked at the parts fiche and your year is all alone as far as rear brake M/C goes. No other year will fit it. So, if you do find a used master cylinder (or two!) I'd snatch em up.

Redox6022 wrote: Does this guy Tim run a business or is it some random dude I call up and ask "hey man I got your number from a forum, you got parts lol?"

he runs a used motorcycle parts place

Redox6022 wrote: I found out from searching around that they do no make a rear master cylinder rebuild kit for my specific year. Can a different year GPz cylinder be fitted onto the bike? The 82 model looks almost identical other that the pushrod going from the brake pedal to the cylinder. Perhaps switching pushrods?

I also have a '81 GPz550 and have dealt with the same problem. I bought a kit for the '82 GPz550 and although I have not installed it, it has the same 14mm bore master cylinder as the '81. It appears that the piston/pushrod can be modified to work or you could try to use the '82 piston seals on your old piston. They are a little difficult to remove, but it can be done. I have not attempted this conversion yet since finding a NOS 43020-1022 piston and seal assembly on Ebay.

How long ago did you get that part? Are they anymore available?