Need HELP 1995 Hino FD 3WLKA.

Hey guys so i am new to Hino trucks.We just bought a second hand 1995 Hino FD 3WLKA and noticed this small black pipe that constantly smokes while the truck is running. When the truck has warmed up it seems to have more smoke. There seems to be maybe oil or something that is driping from the pipe. in the picture attached u can see the small black pipe seems to be connected to the cooling system and the head?. We took it to Truck Stops but got told 2 diffrent things One said that is bad and then another person came and said that it is Normal so we are a bit lost.
Thanks