4 Wheel disc, soft pedal
Check with an assistant for one or both over-returning, is there a visable gap using a small flashlight tight to the rotor & peering in opposite through towards light. If the pins are not moving free(I've seen too much heavy caliper grease develop enuff suction in blind- hole setups to actually pull the caliper towards the bracket & rotor, compressing the piston & leaving a gap between outer pad to rotor.), do the brackets align the caliper(s) with the rotor(s) properly w/o flexing/binding/pushback? Some piston seals drag/hang up in the bore & cause the piston to over-retract when the pressure is released. I've seen all of these in the field. That's where I'd start...good luck! How about a couple pics of the setup..?
