When my car gets hot it spits out the antifreeze out the over flow.. whats wrong with it?

Bleed the cooling system properly and see what happens

I have done that already i think. Does bleeding the cooling system properly mean. -Parking the car on a hill to get all the steam-air out untill it spits stright liqud? We have went out and got the thremtaic for the car. Im thinking its not opening when the car gets hot. Thanks for your help! By the way.

Could be the thermostat -replace it and see what happens