I decided to go ahead and install a replacement radiator in my 2004 Mazda RX-8 despite the fact it arrived with some minor damage presumably in shipping. I've temporarily patched my old radiator but I expected it to fail again soon given its age. This turned out to be a good call! As I started preparing to move the coolant reservoir tank out of the way, its associated radiator fitting broke off.

I learned from RX-8 Club forums this fitting becoming fragile with age is a known common problem, but I was surprised at how little effort was involved. I estimate it took less force than what it would take to break a piece off a chocolate bar. I might have been one bad pothole bump away from this thing breaking on me. In fact, looking at the pattern of dried residue around the break, it was already degraded enough to seep coolant for some time.

My next problem was how to extract its remnants from the hose. Consulting my friend Emily Velasco's experience of working with old machinery, she expected this segment to be just as fragile as the rest. A firm squeeze with some big pliers should be enough to break this apart into smaller pieces for extraction.

Her expectation was correct, it didn't even take much of a squeeze for the thing to fall apart. I had expected to feel some resistance or maybe a "snap" marking the point of breakage, but there was nothing. I squeezed and it collapsed. I pulled out the pieces and tried squeezing the hose again with my pliers. The effort level was basically the same.

I picked up one of the pieces and tried pushing it with my finger. I was able to fold it in half with about as much effort as a graham cracker. Yikes. This thing is long gone.

And that's not the only thing showing severe degradation. Here's a picture I took of the top engine hose fitting after I removed the radiator. It showed discoloration and material degradation similar to the snapped-off reservoir hose fitting. The worst discoloration corresponded to where the hose clamp applied pressure. The base of this fitting was where I found a crack (and applied J-B Weld) and it's pretty obvious that crack was merely the first clear failure and many other potential failures were close behind.

Bottom line: Yes, replacing the radiator was a good idea! And with these broken fittings, I'm past the point of no return. The car is not going to drive under its own power again until the new radiator is installed. Next step: struggling with old radiator hoses.