A fair bit what about the other side of the disc are the guide pins free does the handbrake operate on both wheels are the pads at the other side OK any imballence
I think it's impossible to look on the other side cause there's a shield.
I know nothing about brakes btw. My only concern is a constant grinding noise from both rear brakes when going slow and not braking. I can hear it when driving next to stopped cars or walls.