TOPIC:

Hi, I'm having trouble rebuilding my master cylinder for the KZ. I cleaned it up and reinstalled the original piston assembly as it looked to be in good shape. The brakes are still soft after bleeding.

The bore had some pitting though and I'm wondering how much is ok and how much is too much?

Can someone send me a link for a new master cylinder (aftermarket I guess).

Help,

Thanks,

ill suggest keep bleeding... these things take some time to get all the air out. i used a vacuum pump to bleed mine and it worked pretty good but i still had to hand bleed the last few squirts to get em firm...steve

Pumping by hand took me over a week to get them to feel good enough. Just go out everyday and pump a little more. With the cap off you will see very tiny bubbles coming up. It doesn't seem like much but it's what works.

Hi there, I started a thread on this subject months ago and had plenty of great replies. You should search for that and find some more ideas. I literally tried EVERYTHING suggested but nothing worked. What did work was a trip to a local bikeshop to chat to a guy who raced and owned Z's for years and years.
Here is how to bleed the brakes on a Z900:

First: ensure the bike is upright (off the sidestand) and the handlebars straight.

Second: do short pumps on the brake lever to get a 'pedal' and once you have a firm pedal hold the lever in with the tension on it and use a ziptie (cable tie) to secure the lever in the applied position. Like 'Donthekawguy' said; you will see tiny bubbles. The problem is air in the system.

Third: leave the cap on with enough fluid and wait a day or more. Lastly: before removing the ziptie, apply more pressure, cut the tie and bleed the front brakes. Secure the bleed nipples before releasing the lever and ensure enough fluid in reservoir. Pump it up and check it out.

Like I said, I spent nearly 2 litres of brake fluid, maybe 8hrs of effort, had the calipers off and elevated, did everything everyone said and finally it was the old racer down the road who cracked it. This worked for me and I hope it works for you.

Did you have to elevate the calipers above the master cylinder? Thanks for the great tips.

David