Heater Core

[amora]

Hi!

This is a picture of my heater core - in the front i have removed the aircleaner.
Can somebody tell me, if the warm water goes in the heater core at the upper tube or the lower tube?? Which one is the tube, where the water comes from the motor?


Thanks

 

[TexasRammer]

I believe the upper tube is where it enters the core

 

[amora]

How can I check this by myself?