Seems like the plastic elbow which connects the radiator to the expansion tank on these cars (W124?) breaks frequently judging from the posts on this and other MB forum sites. Mine recently gave out, and I found it easy to replace once I'd removed the top radiator hose (thanks to help I found here).

The problem now is the radiator leaks around the plastic elbow, that is, the pressure causes coolant to squirt from around the elbow. I have to fill the expansion tank about every 15 miles ... not a good situation, but I'm just trying to make it to the weekend when I'll have time to fix it properly.

I've thought of using epoxy to seal the elbow to the radiator, but wonder how it would hold at operating temperature and then what I'll do when/if the elbow breaks again. Don't know what MB mechanics use for sealant when they replace this part.

Any advice ... much appreciated.

THAT LITTLE ELBOW COMING OFF THE TOP OF THE RADIATOR IS REMOVEABLE AND HAS A RUBBER O RING ON IT. ACCESS IS THRU THE LARGE RADIATOR HOSE BEHIND AND BELOW THAT ELBOW. OR YOU CAN BUY THE WHOLE PIECE FOR $2.