I have a 2001 Cherokee and I'm having a problem with the radiator. The original one I had cracked on the top of it on the passenger side. I replaced it a week ago and today it did the same thing. I don't know why it keeps doing it, I have replaced all the hoses and the thermostat and the water temperature gauge stays right it the middle. What do you guys think it is ? Could it be the water pump or could it be something more serious?

 

You say the new radiator cracked in the same place the old one cracked? Did it slide easy into the bottom pin holes or did it fight you on the way in? the radiator should "float " in the mounts and not need to be forced into position. Or the new radiator might have been defective. Hope this gives you something to look into.