Caliper sticking - take off caliper and try to push back piston into the caliper bore (if possible with the bleeder open)
Flex hose restricted -Remove from caliper, take lid off of master cylinder and see if fluid runs out at a good pace (don't let it go empty)
Pads stuck in caliper hardware - remove caliper and make sure pads move freely. Calipers may act different from hot to cold, when does it not release? Check it when its acting up.