yanmar 3ym30 heat exchanger

[RobD527]

anyone has ever seen this happen?

I just spend 2hrs doing yoga to fix a fuel tank problem and after that thought why not check my coolant. Well the radiator cap was stuck and of course, I twisted the whole thing off the top of the heat exchanger

I'm thinking clean it up (JB weld) and self tap screw it back down or take it off and let a radiator shop weld it back together?

Any suggestions?

[Lepke]

A radiator shop would do a more permanent job. I suppose it was soldered on, brazing would be better. Maybe silver solder. I can see removing the HE is a pia.

One option is plug the hole and install an inline cap housing in the hose. About $20-30 on eBay.

[RobD527]

I wish I had known that it was replaceable before I JB Welded it back on. I figured out that it is called a coolant fill neck.

If my fix does not last at least now I know now the name of the part and can get it ordered

[tkeithlu]

PIA or not, Rob, I've gotta wonder about the condition of your heat exchanger. That bad corrosion at the cap suggests a nasty situation inside, which may interfere with proper cooling. It's like finding rot in a piece of wood - worthwhile digging further until you find good wood, rather than just treating the surface.

Sorry to be coming forth with a discouraging suggestion. It's your call, because it's your PIA.