Rear brake pedal froze up.
Rear cylinder froze or ABS??
Happen to anybody??

Heat degradation is my guess. What happens is the buildup of this white crusty powder forms under the seal. Locks the piston from retracting back to square caused by the quad-seal's memory made of rubber.

Cut the circle of the seal and the end cut looks square box like. Water is heavier than oil so it settles at the lowest point, being the machined grove for the quad seal. Thus the memory to relax back to that square or its upright position.

As you push the piston out the quad rises up from the bottom like this [ // ]. The quad can pull the piston back to square like this [ || ] when pressure is released. But this crust buildup is locking piston in one direction and never pulls back off the pad.

Test to see if it's the master or caliper. Just snap the banjo bolt loose at the caliper. If wheel spins easy, it's the master. Wheel stays locked, it's the caliper quad needing a cleaning of that groove. Pull the quad ring out, seal up the banjo bolt hole, fill with vinegar and a little bit of hydrogen peroxide: let it sit overnight. Rinse with water and blow dry with compressed air.

Go outside and reflect the sun's rays into the groove to see if the grove is clean of the white buildup. Scrap with an ice pick, scribe, heavy gauge sewing needle. Spray away with contact cleaner and watch it evaporate in the sun. You can see leftovers where you missed. That or scrap before using the vinny and oxide.

Begin with the calipers. No sanding of any piston or caliper's machined inner surface. Wipe with a paper towel any liquid crud inside. Remember, vinegar expands any rubber.

I am starting to see more of this issue with customer bikes here in the UK over the last few years!

Always on the rear brake circuit. Never the front.

The shuttle valve inside the ABS unit seizes and locks out the rear brake activation.

I use a company here to strip and refurb the ABS units. Way cheaper than the £1,603 that Kawasaki want for a new unit!

Had another customer contact me literally today about this on their 2016 bike.

https://controlunits.co.uk/kawasaki-abs-hydraulic-valve-block-repair/

Yes, its ABS pump failure.
Kawasaki says they might help,
I have to go through dealer,
Only one unit in US, sitting on a dock somewhere..
Thx for your input

Does the 14R work without anti-lock brakes? You could buy a whole new aftermarket rear brake system that weighs less and is more effective for less money than replacing the OEM one. Only problem, I don't think it's going to be compatible with ABS.

Yes you can bypass Pump-but will end up with ABS light.
And no ABS

Thanks, hawkman. I'm sure the light could be gotten rid of too. I still don't know how I will like anti-lock brakes having never tested them on my bike.

You can bypass the rear abs line, with just a braided line.

This keeps the pump unit connected, so no warning lights on dash!

I still don't know how I will like anti-lock brakes having never tested them on my bike.

Rook, you'll love it. Especially when you bark down on the lever and the bike stays upright under hard (panic) braking. Bike makes these tiny electronic bleeps and can hardly feel the pulse releasing/reactivating.

When BMW first came out with ABS, they had a test platform and the bike hooked up for testing. I hammered the front brake and it chattered hard. The 14 took care of those harsh pulses.

Good to know we have smooth anti-lock brakes. I had the tail hover under hard braking on my Gen1 and I kind of liked being able to do that. As for the fronts, they lock up before the bike flips. I think you'd have to try to do a stoppy on a 14 or a busa because my experience has been, the front brakes lock and smoke the tire long before the bike would come over. If that's the case, anti-lock brakes are going to produce the maximum stopping power on one of these bikes. Maybe it's just what's best for this particular machine but without becoming aware of how ABS might impact my riding experience, I'd go with non ABS. I became familiar with the non ABS brakes and when time came to find the limits on the few occasions I did, I was able to do it. I have no doubt a bike is going to stop in less distance with anti-lock brakes though. With non ABS brakes, I was modulating between skidding and braking and that eats up some distance at higher speeds, I'm sure.

Me Lucky Boy!
Kawasaki steped up and replaced abs pump.
$125 out of pocket.
Let The Good Times Roll!