I have Wilwood Superlite 6 piston calipers. I just installed a new set of 14" rotors and have new brake pads. With new rotors and pads I need to fully compress the caliper pistons for clearance. Unfortunately I can't get two of the pistons to press in. I've tried several ways of pressing with a clamp and old brake pad, block of wood, etc.. with no success. Anyone with these type of calipers have this issue before?