Need some help and info

Okay so i just got my first bike it's a 82kz 550 lots and one issue I'm working on fixing is the front brake was locked up so I took the caliper off made it so it could go back on the rotor and re attacked everything and I went to bleed them and they won't build pressure so overuse came to the conclusion to get a new master cylinder and lever. Cool but my question is could I just put the one in he picture on there rather than buying a used oe one that I won't know if it works or is junk or what are myoptions. My next question is what is the this thing in the other picture I had a short in my harness and chased it down to coming from this and need to know if I need it or can I just unplug it and junk it and not have to worry about it. I'm new to the whole forum thing too so this is all new to me

this is the master cylinder I was looking at

And this is that part I was asking about

No eBay APP ID and/or Cert ID defined in Kunena configurationI looked that up on eBay at

It says the bore is 17mm. That is not the correct bore size; I would not buy it. I believe you will find the correct bore size for a single front disk brake system is 14mm, and it is 5/8" (15.9mm) for dual front disks. I have no idea what a 17mm bore is used on, but it's definitely oversize for use on any KZ I'm aware of. Ed

Welcome. The next thing you need is a manual. It should identify that relay.
Steve

You want a 12.5mm or 12.7mm master cylinder. Replace the brake line as well. A new braided line is not expensive.

650ed wrote: the correct bore size for a single front disk brake system is 14mm

A 14mm master cylinder may cause high brake lever effort.

You may not have pressure if your piston is tight inside caliper, replace seals, check piston for pitting. Just finished my 82 gpz 750, i had pitting on both pistons, they were tight inside caliper. Use air compressor to push air into caliper to push out piston, use a block of wood to prevent piston from flying out. Check and clean caliper, replace seals, DONT use brake cleaner on rubber parts, they will swell up and seals will be useless. Try that first, a frozen piston wont allow piston to move if its seized. I did replace master cylinder, most of the problems were at the calipers, bleed system several times.

The relay was under the battery box if that helps and is any recommendations on where to get a manual?

Loud has them in his signature. Look up kz 550 manual.
Steve

The_Proletariat wrote: You want a 12.5mm or 12.7mm master cylinder. Replace the brake line as well. A new braided line is not expensive.

650ed wrote: the correct bore size for a single front disk brake system is 14mm

A 14mm master cylinder may cause high brake lever effort.

I don't understand your statement. I am under the impression that the original MC bore for the single disk system shown is 14mm, so why would that cause high brake lever effort. Didn't every KZ bike with a single front disk come from the factory with a 14mm bore? Ed

No eBay APP ID and/or Cert ID defined in Kunena configurationSo this one would work then?

According to the listing it is the correct size for a singe disk system. It say says it replaces MC with bores from 11 - 14mm, so if The_Proletariat is correct about the 12.5 - 12.7 mm bore it still falls within the range listed. You may want to verify with the seller before buying. Ed