I just got back from a 600 mile vacation. No problems, I thought! I was out washing the car, dried it off and went on a 5 mile errand. When I shut the car off, green antifreeze started pouring out!. I can't see where its coming from. I started the car and filled the water reservoir with water, didn't help, steam started rising and I heard a squealing noise, the temp started going up so I shut it off. Is this a water pump problem or something bigger??. I got to thining that on the trip I did hear a hum when the air conditioning was on but it sounded kind of normal, not any kind of squeal. What do you think?.