Taking my '73 Spider out of hibernation here in Oregon where winters are damp and the front brake calipers are holding onto the discs. Not completely bound (with the wheels off the ground I can rotate them ever so slowly with great effort) but the car does not roll freely as it should. I have less than 2,000 miles on a complete brake rebuild of calipers discs and brake pads. What gives? What is the mechanism that should spring the pads back to the "off" position?