Z900 A4 brake caliper pistons

[hondasan]

My UK 900 A4 needs new brake caliper pistons. Plenty of pattern ones available, but they all look different to those that came out of my callpers.
Mine have an inner "puck" with a slight dome on it that pushes onto the metal shim on the back of the moving pad. All the pattern ones appear to be hollow, and so will contact the pad around the outer edge of the piston? Or should the inner puck remove from the old pistons and fit into the new pattern ones (One has come out, the other is well stuck in there)?
Wanted to check before spending the money!

Thanks - Chris

[Philippe]

Hi Chris

I think that the original Z 900 A4 caliper pistons had no "puck" inside but were hollow. If I'm wrong, there are others that will correct me.
The "puck" in the caliper pistons appeared when Kawasaki started to use metal sintered brake pads.
The "puck" was ment to isolate the caliper and the brake fluid from the extra heat caused by the sintered pads when applying the brake.
So if you want new brake caliper pistons there's a big choice out there.
GrtZ
Philippe