I'm having trouble with installing my upgraded rear Wilwood e-brakes Model 140-15138-D. I've got the IRS package.

When the brake is engaged with the handle, the pads clamp down well enough, so the rotor doesn't turn at all.
The issue is that when i dis-engage the lever, the brake piston & pads don't move back to their original position.
I couldn't slip a piece of paper between the rotor & brake pad when disengaged. I don't know if this is due to the cable being installed incorrectly or what, but this driving me nuts.