I just had the transmission rebuilt on my truck. I noticed that the top cooler line after pulling a few hills with my camper is very hot to the touch and the bottom line is just a little warm. Is this normal ? I know for a fact that the cooler lines were blown out with air.
I am going on a camping trip this weekend and am a bit worried.
Thanks in advance

 

it works like a radiator,
hot - in
cool(er) - out
providing cooler fluid for the transmission
thats its purpose
working fine