Sorry if this post is in incorrect forum.
2016 F-150 XL 5.0L V8 Flex Fuel
Picture was taken from passenger side.
Red circle is the upper radiator hose.
Blue circle (i think) is the radiator end near passenger side.
In the blue circle, there is a somewhat dried up coolant residue. I took my truck to shop. They said change water hoses, thermostat, water pump, serpentine belts. I did all that at home. no problem. but that somewhat dried up coolant residue is appearing again. Do I need to change the radiator?