With pads and a rotor in place the inside pistons don’t self adjust, which eventually leads to the calliper itself being pushed sideways until the inner face of the calliper contacts the disc- a net sideways force is exerted, basically.
Sticking this hex wrench in the calliper and operating the lever shows that once the outer pistons have emerged the inner ones will then do so.
With pads and a rotor in place the inside pistons don’t self adjust, which eventually leads to the calliper itself being pushed sideways until the inner face of the calliper contacts the disc- a net sideways force is exerted, basically.
Sticking this hex wrench in the calliper and operating the lever shows that once the outer pistons have emerged the inner ones will then do so.
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