Last week I flushed the coolant in Boxy (1982 300SD) and had great initial results - much better cooling performance, less temp variation, etc. Got to work last Thursday and saw a small leak on the upper radiator hose. No biggie, I think...must not have tightened the clamp enough and of course, the clamp was a bit loose. So I tighten it down, not thinking much about it. That night, I drive down from CT to PA (I do this regularly) with no problems as far as I could tell. Spend the night, etc. Then, Friday comes around with its 90 degrees and I notice coolant dripping pretty quickly from the upper hose. Just tightening it, I wasn't sure what it was, but it was a bit loose again so I tighten...and it begins to gush out. I quickly/carefully released the pressure by the cap to get it to stop gushing....let it cool down and I take off the upper hose.

The upper radiator neck had snapped clean off . I had to fish the end out of the hose. My fears were confirmed when I jumped on here to see if just the upper neck was replaceable and indeed it isn't - I will be ordering a new radiator. For now, I've JB-welded the neck back on, about to give it another coat of JB to stop any pinholes. Obviously just a temporary fix that should just get me around town if I need it. Anyone used JB-weld on a radiator neck before?

Now, the lesson:
DO NOT OVER TIGHTEN YOUR RADIATOR HOSE CLAMPS!!!

Or fear the wrath of being stuck in one place and spending lots of money!

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth