Gear Issues 337B

[Jhogan0101]

Having some gear issues…

-Gear started to cycle slowly.
-This plane has the optional rear gear pump installed
-Took plane out of service for some avionics replacements, its been out of service for about 11 months.
-Trying to get the plane back up and running now.
Recently:
-Both front and rear hydraulic screens were cleaned, not a lot of debris.
-Front nose door actuator was leaking, actuator was removed, rebuilt, reinstalled
-While actuator was removed, alot of hydraulic fluid came out of the system
-New hydraulic fluid was filled after actuator was reinstalled, filled until started to pour back out.
-Manually pumping the doors open/closing is normal, no leakage.
-While doing some test runups, no flights, after shut down, there is quite a bit of hydro fluid on belly coming out of the hydro vent on the front/belly of the plane. This was without touching the gear handle at all.
- Next time running up, while idling at 1200 rpm on both engines, i pressed the gear handle down. It took any where from 5 to 10 secs for it to snap back up to down neutral. During this, hydraulic fluid was dripping from the vent, i confirmed before that the fluid was halfway on the site glass in reservoir.
- While flying i had to physically hold the gear lever up to complete the gear retraction, had to hold gear handle down to complete gear deploy.

Not really sure whats going on here, my a&p and ia are also stumped. Any ideas as to what might be happening? The power pack was rebuilt about 100 hours ago by previous owner.