Did you swap out the thermostat too? Often a good thing to do since it's right there when you do the hoses. Vacuum fill if you can. Minimally, you need to run it for a while with the cap off to allow air to escape. Wait for it to get up to temp, allow the thermostat to open and coolant to flow throughout. Others have recommended parking it on an incline, nose up, to help push the air to the highest point (open radiator cap).