loosing a little coolant on 2012 5.0l. only thing wet is this device. radiator hose hooked to it and bolted to water pump. I am unsure what it is. anyone ID this dribbling device?

 

wear from Pressure to Vacuum Try them first and if it still leaks look up the 5.0 Tee Leak

 

Your picture shows the thermostat housing.

 

this is better angle showing coolant on bottom of unit. Given that the truck has 150k, is this just O-Rings or replace plastic T and metal housing?

 

As long as coolant isn’t leaking from the seam of the plastic T you can just replace the o-rings for it. In your case I’d replace all the seals, and if it hasn’t before, the water pump.

 

I had one of the big hoses replaced a couple of years ago (don't remember which one), everything else is original. I had not thought about the water pump. I guess that there is not much additional work to pull the pump once you are that far in.

 

Getting leak fixed Thursday. Going to put water pump on anyway due to miles on truck.

 

from original post in 2021 I have now replaced water pump and every hose. OEM from 2012 to 2021 then within 2 years they all went. Oh well, should be good to go until 2024 lol