Just got my 2012 Mustang and am prepping for my first track day. I purchased some HP Plus pads and installing the fronts was a breeze.

When I moved to the rear, first, the caliper took a TON of forced to slide off the pads. When I put in my disc pad spreader to compress the piston, the piston would not recess back into the caliper even after a TON of pressure. I even tried loosening the bleed valve and the caliper still would not budge. I tried hard enough that my disc pad spreader even broke.

This happened on both sides of the rear, as well.

Can anyone tell me if this may be normal and perhaps I'm missing something???

 

The rear doesn't push in. You need the tool that turns it. They "screw" back into place, unlike the front pistons

 

^ Yup. Go to Autozone or wherever, "rent" their brake caliper tool and the piston turns clockwise while applying pressure to push it back into the bore. Don't bother with that stupid $5 square thing that attaches to your ratchet, it is completely useless.

 

Cool...I was just missing something. Thanks for the quick answer to my problem!!!

 

it should look something like this