I have a 94 Eldorado that has an overheating problem. I changed my lower radiator hose because it was wet and I changed the thermostat while I was there. My question is why my coolant doesn't seem to circulate at all. After the car gets up to 200 degrees I squeeze the upper radiator hose and there is no pressure. I originally thought the pressure was just low so I pulled the upper radiator hose off and it is dry as a bone. I looked at the impeller on the water pump and it looked like it was OK all the blades are there and complete. Is there a screw to bleed the air out of the coolant system or does it just purge through the overflow? The radiator was changed approx. 1.5 yrs ago by the previous owner so I don't think it is clogged. Am I looking at head gaskets?? In the past when I had bad head gaskets there was still flow through the cooling system but I know nothing about the N*. If it makes a difference there isn't any white smoke out the exhaust.