We discovered this during a recent Deco-mainte visit.
Dust seal protrusion
Corrosion inside the seal pushes the seal out.
The piston is rusty too.
The interior is far more gunked up than expected.
I scrape off what I can with an ear pick first.
Then I polish with a brush on the rotary tool. Polish, polish, polish.
The inner wall is heavily corroded and rough.
I apply metal rubber and reassemble. ☆
And there we have it—a smooth-operating rear caliper!
