Rear brake pad seating issue

[Jimmy B]

I have the #16765 Mustang 2015-new IRS w/11.65 rear brake option from FFR. The pads sent along are the Stop Tech Sport 309.05450. These pads with these shims (modified as described) do not fit these calipers. Has anyone else run into this?

[SteveWorth]

Jimmy
I had to file/grind the edges of the brake pad backer in order to get them to fit.
Steve