While replacing the water pump.....the metal tube attaching the water pump to the engine seems to have rotted off and broke. How can I tell if I need to buy a new one? And if so....what EXACTLY is the tube called?

Yes replace it if it's that bad. It's called a water pump inlet tube. Make sure you have the gasket and everything for the water pump and make sure to get the air out of the system when your done. Look up some YouTube cideos, there's some on there for how to do this.

Thank you MNOE. I'm replying here for hubby, who's gone to bed. LOL.....he knows a lot more about this stuff than I do, but just trying to help him out by trying to check things out. Thanks for replying!!!!!

If the pipe is broken off at the threads, it's usually easier to buy a new pump rather then try to remove that short piece. You probably need one anyway. If this is the straight 6 cylinder, be sure to get a premium pump with a METAL impeller. The plastic ones tend to shatter when the bearings get a little worn.

BTW, welcome to CF!