Mobeartec L2x-Brake Mod-Kit Benutzerhandbuch Seite 10

First remove the two screws, using the 2.5mm hex wrench.
Then carefully move the upper part a bit out of its location
to release the tension of the spring inside the piston.
After taking off the top, you can see the spring and a rubber
damper inside.
Img 3.2.2: Original spring and rubber damper..
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