Top where? Sounds like the plastic end caps of your radiator are shot

 

I haven't take the bumper off yet to get a better look but it was pouring out liquid as soon as I put liquid in the tank. I am more concerned with the process of how this has come about. It started with one pinhole leak in the hose from the reservoir to the engine. After I replaced that hose a few weeks later the bypass valve went, and now a major leak from the radiator. It seems like the issues are just running around the coolant system...

 

Looking for a coolant leak will not be helped by removing the bumper.

From what i have read in this thread so far I would do a pressure test on the cooling system and find all leaks and weak points.

You may have a head gasket issue given that hoses are failing and things are over pressuring.
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Sorry meant the front end bumper, where the radiator is. I would think the same thing but the engine hasn't overheated once, nor has the tank bubbled/overflowed with coolant.

 

the plastic end tanks on the radiator are just glued on and they can leak. Look carefully at that.

Do you know how to do a pressure check?

 

Ok so I took the radiator out and the housing from the top of the radiator was pretty corroded. Turns out there was a large crack on the plastic seem going down the radiator. I have ordered a new one and hope to replace. I don’t believe that the crack has been there for very long... any thoughts on what could have caused this? Or was it just old and need to be replaced?

 

very common type of radiator failure on these cars. Just something that comes with this type of construction.

I have a full aluminum radiator in one of my 9-5 Aeros and love it.

 

I said this last week to someone else (you?) that it sounds to me like you have a bad head gasket. Successive failures in the cooling system is likely due to over pressurization of the cooling system and as soon as you replace one part you're going to have another fail.

I suggest you get a testing kit that allows you to look for combustion by products in the coolant (once you get the radiator on) to see if you have a bad head gasket. But given the succession of different parts of the cooling system that you are seeing fail it's likely you have an issue.

 

Successive failures in the cooling system is likely due to over pressurization of the cooling system and as soon as you replace one part you're going to have another fail.

As per post number four. ;ol;
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The end caps will die from old age. I think you have no choice but to put in a new radiator and see what happens. It would be rare for 2.3 engine to have a head gasket leak unless the car had a significant overheat in its past. I’m optimistic for you. Btw, a head gasket leak can be tested with dye strips in the overflow bottle