Brake caliper pistons

[glenn]

Do MB caliper pistons rotate on any newer models???  Just replaced the brake pads on a '05 Honda Accord.  The (single) pistons rotate as the pads wear.  Cool, eh??

[Benz Dr.]

I can't say for sure on newer cars but they aren't on older cars.

 The piston is positioned a certain way so that when the brakes are used the front of the pad hits the rotor first. This feature requires that the pistons remain in the same fixed position so the brakes work as designed.

[Bernd]

Dan is absolutely correct. They are not designed to rotate. Also, there is an installation aid that is basically a triangular piece that has a 20 degree bevel which helps in aligning them properly. If you look at the enclosed picture from my front ATE caliper piston you will see the raised portion at the rim. That is raised so that the pistons do what Dan indicated