I am new to the mustang world and looking for help. I just got a 2002 GT with 64,000 miles and it was wrecked in the rear. I have fixed that and have been trying to get it on the road but having issues with it. when I got it there was a hole in the radiator and there was no antifreeze in it. So I put a new one on and filled it up then there was a lot of air in there and I think I finally got that out last night. But it seems to be building up pressure still because it is coming out the little over flow hole under the cap. could there still be air in there causing this or do I have bigger problems?