I have a 1998 Silverado 5.7 w/ a lil over 240k. I've recently ran into a coolant leak. It appears to be external. I've checked the oil and it's fine. First it was leaking right under the water pump so we replaced it and the gaskets. We replaced the two little hoses on top of the water pump. The two big lower hoses look fine and don't appear to be leaking. Well now the leak is near the front bumper/driver side. Any ideas? The only thing close to the leak is the small metal tubing coming out of the radiator going towards the bottom of the motor. Is it possible that the metal tubing coming out of the radiator could be leaking? Thanks in advance.

 

There should be 2 metal tubes going into the radiator. They are the cooling lines for the transmission and have transmission fluid in them not coolant.