after turning on heat for a few minutes my belts started squeaking. On my way home from work my squealing continued and I barely made it him. Temp did not make it to red zone just to the upper side of temp icon on gauge. Truck was steaming. This morning we found that the radiator was almost dry and found a little larger than pin size stream coming from a piece that looks like it "screws" into water pump? Can I replace this piece or do I have to replace the whole pump.
Move attached two pics. An over view shot and the other you can see the piece that's leaking. It's located under the red thing. Yeah yeah I know but I don't have a name for it. Thanks in advance Piece under red thing is what is leaking
Just an overview to see location

 

You're pictures are so big, it's hard to tell what's going on.
If the water pump is leaking, there's nothing on it that can be replaced that will stop the leak.
You need a new water pump.
Other things to check is the lower rad hose and clamp that attaches onto the front timing cover.
That is a common source for leaks.
It's quite possible that may be the only source for the leak.

The Front timing cover gasket can leak too.

It's from 2001 so 16 years old, so it's time for a new pump.
How many miles does it have on it ?
Assuming it's an automatic.... Not that it matters in this case.

If it was my truck, I would just get in there and replace the front timing cover gasket and pump.
It's a big job when the timing cover gasket is removed, it can disturb the oil pan seal _ so another can of worms.

Sorry to be wet blanket, but all of these are common issues as the 3 liter ages.

 

EDIT:
I think I figured it out.
The piece under the red thing is where your temp sensor is screwed in.
It's made of steel so it can rust where the sender threads into it.
There are also a number of hoses there too that run into your heater matrix that can develop leaks if the hoses are gone.
It's also possible that the sender itself is leaking, but unlikely _ should be checked though.

 

thank you! That makes sense as it does look like it is screwed in and the leak is coming from that piece. This did occur moments after the heat was turned on for the first time though I had used the defrost a few times prior

 

At any rate, carry some water with you, you don't want to ruin your engine in case it over heats again.
Usually a couple of 4 litre jugs.

I still think there is a more serious leak going on here, there's a lot of coolant on the belt for such a small leak, but start with that area you first suspected.

 

thank you. I did but can only get about 4 miles down the road which was as far as I needed to go thankfully. The mechanic in my neighborhood confirmed problem so I said it's all yours! He said he would look at the hoses too. My husband said thank you as well. We both did not want to tackle this job! I haven't worked on a car since the late 70's very early 80's and they sure have changed

 

Keep us posted to the exact problem after it's fixed, it will help others with the same problem.