Hawker800a

I have a 112A s/n: 327 that the nose gear will not retract. I have replaced all Orings in all the actuators, replaced power pack, the gear will not move unless I push the drag brace. It unlocks the downlock on the nose gear actuator but will not bring gear up unless I push on drag brace. Anyone have any idea? I've checked for blockages, made sure emergency valve operates. Had the gear up for 48 plus hours and nothing fell out of wheel wells. Once main gear comes up powerpack shuts off and when i push drag brace it'll start up until it hits uplock switch. All lights work accordingly.