On my 94-Max when engine cools down coolant is not coming from the the coolant expansion tank back to radiator. I checked for hermetically sealed connection and air buble in radiator.
Is it the problem with radiator cap, which servers as a valve on that line? Should I replace it?
Thanks for an answer.

 

you can do a pressure test on the radiator cap...pretty simple and you should be able to borrow the tool from kragens

 

I had same problem...it was the seal between the top tank and aluminium core of the radiator. It was only weeping a little but it was enough to disrupt the flow of water back to radiator. I agree with Medic, get hold of a pressure tester to pressurise radiator and look for leaks.

 

Guys, thank you for ideas.