The brake disc must be replaced if its thickness becomes less than 9 mm.
Removing the front brake caliper (see Front wheel brake caliper replacement), without disconnecting the brake hose from it. We tie the caliper in a convenient place so that it does not hang on the hose.
key «at 12» unscrew the two guide wheels.
Remove the brake disc and spacer.
We install a new brake disc in the reverse order of removal.