As a cheat, you could try to partially apply the E brake to take up some slack and test. One thing about the E brake on the Stang calipers is that it only works with a certain amount of clearance, too much and it will not work. Too little clearance will cause the pads to drag and heat up.
I found out about this the hard way, replaced the pads, which requires rotating the piston all the way in, poor brakes and no E brake, till I adjusted them properly.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
