Help with coolant issue after radiator changes
 

Just replaced all 3 radiators, used a pressure tester (no leaks) and a vacuum tool to refill. Was able to add exactly the same amount in as came out. When the car is warmed up it stays steady at 180 for an hour so no overheating issues, but the coolant tank level drops a bit until i remove the cap and relieve the pressure it goes back to where it was. see vid
​​​​​​ When i got home the bleeder valve was up, but no air was coming out (bad bleeder valve?)

thoughts?

That doesn't look significant. You may have a little air trapped somewhere that will eventually work its way out, but if your temperature is staying at 180, all is good. (...and you were able to confirm that your cap is good)

My 2003 Turbo received 3 new radiators back in Jan. 2015. The work done at a dealer. No issues so I have no direct experience but the cooling system needs to get hotter than 180F ( and you need to confirm this using an OBD2 code reader/data viewer/logger connected to the OBD2 port and configured to query for coolant temperature every so often) so the T-stat opens fully and coolant is circulated thorough all the cooling system.

I had the Turbo cooling system drained and refilled 3 times (one time after hitting a mule deer, after a water pump was replaced, and after the radiators were replaced) and the 2002 Boxster's cooling system also drained and refilled at least 3 times (maybe 4 times) and after every time I made it a point to drive the car normally -- with the A/C off -- and around town until the coolant was hot. Hot enough to trigger the radiator fans to come on which I knew from observation happened at 212F.

This was to make sure the system was fluid/pressure tight and to make sure there were no air pockets. I never found any the vacuum lift system worked like a charm to properly fill the cooling system with no air pockets. But this may not be the case for your car.

Jack the rear of the car and let idle for a while with heater on full blast. Air tends to collect in the heater cores and the best way to confirm is with heater on. If the heater temp fluctuates or never gets hot you have an air bubble in the heater core. With the rear elevated you should be able to burp the system. If not by idling then use the vacuum servicing tool.

all that happened was you didnt get the system properly pressurized after you re-filled the coolant. this results in coolant escaping and you still have the valve UP.

time to CLOSE the valve at the cap and top off, if or as needed.