Once again I come before the all-seeing, all-knowing Brickboard for knowledge...

First off, I apologize if my terminology is incorrect or confusing.

I have an '83 245 that is leaking coolant like you wouldn't believe (well, maybe you'd believe it, but anyway...). I think that I have determined the cause--it is a metal tube that attaches to the radiator at the top, passenger side through some kind of fitting. It is this fitting (a 27mm nut) that appears to be leaking--when I apply pressure to it (say, move it a little bit up), I can see the fitting move and fluid come out (the frequency of the drip-drip in the bucket underneath the car increases, too).

I can't seem to get this fitting off--I can unscrew the female part of the tube, exposing the male part and access to the large nut that appears to be holding the male end to the radiator. But when I attempt to remove the nut and male end, all it does is spin and occasionally get tighter/looser. None of this helps the leaking, but it does sometimes make it worse. This tells me that something in there is stripped--somehow it's not attached correctly.

My question is this: I have a radiator in an '87 car I use for parts. Would it be easier to remove this radiator and replace the one in the '83, or is there some technique that might help me remove that male fitting so I can just replace that?

Many thanks again for any insight you might offer!

Milan
'83 245 (130k), '86 245 (195k), '88 760GLE (220k), '87 245 donor car