Let’s improve the operation of the caliper pistons and get a better feel at the lever.
Heavy corrosion usually happens on the back side of the dust seal. If it’s anodized, you can prevent quite a bit of it, but without the treatment you get what you see here.
It’s pretty harsh. When you have the pattern of “piston operation is poor → caliper cleaning → slightly better but gets bad again,” I think it’s good to replace the seals of course and also smooth out the unevenness from internal corrosion.
Creating an environment where the seal isn’t deformed by foreign matter (corrosion) and reducing resistance between the piston and seal for smooth operation gives you a good feel.
The rear caliper is anodized, so you can see there’s much less corrosion.
Just because it’s new doesn’t mean you should assemble it like a plastic model kit—that’s pretty dangerous. You always need to visually inspect it.
I’ve actually had seals of different diameters mixed in before, so never taking things for granted is what keeps you safe.
Even the tiniest mistake can slip through.
