firstly hello again omega brothers!!

car is 2001 2.6 v6 elite
i completed doing the oil cooler change and removed nearly all the water pipes to flush the sludge out under hot tap so as to give the rad flush a fighting chance..
put everything back 2gether as meant to be.filled water up and flushed out a few times.(letting engine reach running temp everytime).
now i'm trying to fill the system up for the last time.
thing is when i first drained the system loads n loads of water come out but every time i fill her,run her for a bit fill abit more.keeping cap off!!at a certain point the water starts to push up and out!!.is that rite(is that when the thermostat opens??)??so i put cap on run her for a bit cool, down and take cap off but she dont seem want any more water ? top hose and bottom go hard when at running temp.so i'm sure the thermostate is openning(inspected thermostate whilst engine woz stripped and it woz almost brand new!!) does it take several days and numerous inspections to finally get all air locks out? :-?..
but at the mo theres defo not as much water gone in as first come out??
all feedback is greatly appreciated as always ma freinds!!
thanking u muchly lads!!

cheers...
wes..