Wierd Kawasaki brake problem...

[tkent02]

Got some used twin pot calipers to put on the 1100G, with Salty Monk's little conversion kit. Everything fits very nicely, it's all good there. Bled the brakes, no air, the brakes come on when you squeeze the lever, but don't release when you let go. Open the bleeders, they release. As you pull the brake lever lightly a few times, the brakes go on more and more with each pull, but never release. Could not come close to getting the caliper off the disc without opening the bleeder. So I let it sit overnight, the caliper is still clamped onto the disc, although not as tightly as the night before, I could struggle a bit and get the caliper off the disc.

Sounds like a blocked return port in the master cylinder you say? Well it's not, the master cylinder worked perfectly with the Suzuki calipers before I tried this swap. And now it works perfectly with the Suzuki calipers back in place. The inside of the master is clean as a whistle, with no crud anywhere. Nice clear brake fluid. And, it has braided steel brake lines in good shape, replaced a few years ago.

Who's got an idea about what might be the cause of this malady?

[FreshStart]

Rebuild the caliper?

[tkent02]

That's the logical next step, it just seems strange that both calipers would have exactly the same problem.

[Nessism]

Almost seems that the master piston is not retracting enough to open up the return port.

[Big T]

Probably because they're filled with the same 20 year old crud and have 20 year old seals around the pistons

[sharpy]

Yep it be the caliper seals/crud. Have fun scraping ALL the corrosion behind the seals. Little wire wheel on a dremel is best wise a dent sharpened old spoke to get in there followed by some fine steel wool. Hoping the pistons arent pitted. Good luck and have fun.

[hampshirehog]

What I can't explain though is that the pistons back off when the bleed nipple is opened. But I think strpping and cleaning is inevitably going to be the first step in trying to work out what's what.