Radiator Overflow Elbow - 300E
 

I recently tried to fix a broken radiator overflow elbow on a 92 300E. Thanks to the fine search capability and the wealth of information on this forum I learned that I was not alone (!) and was able to figure out a temporary fix.

Now, what to do to fix it permanently? I've purchased a new plastic elbow from the local MB shop, but of course the broken off piece is still wedged in the radiator. Is there a way to remove the broken off piece, should I push it through into the radiator, or should I plug it permanently? If I plug it permanently, what happens to the overflow that would normally go into the expansion tank? Do I care?:confused: Please advise ... any help much appreciated.

Steve

Failure of this plastic elbow is fairly common with age. Often the broken pieces will fall into the radiator anyway (as was the case with my father's '93 E320). I am not aware of the small plastic pieces ever causing any problems (others may wish to comment), nor am I aware of anyone trying to retrieve these pieces once they have fallen in. I would be inclined to suggest that if you cannot pull the broken piece out, then I would push it in. I would advise against trying any mod such as plugging it permanently. The designers put these things there for a reason.

Looking for some additional advice on the pesky radiator overflow elbow on my 300E. I had decided to use the valve stem repair idea (elsewhere in this forum) for my radiator, but discovered that I could easily remove the broken off plastic elbow section once I had removed the top radiator hose.

Having already purchased a new plastic elbow, I installed it after removing the broken piece. I also installed a new radiator cap on the expansion tank and thought the problem was fixed.

I quickly saw that coolant was escaping somehow from the expansion tank ... to the point where I need to fill it every 10 miles or so. There's not a lot of liquid under the car when I park it ... but it's kinda difficult to determine whether what's under there is from the a/c (I'm in Texas) or is coolant.

It appears to me that the plastic elbow isn't sealing correctly and that it is spurting water over the engine when I drive. Temperature stays in the 80 - 90 degree Celsius range.

I'm driving it this week (with several gallons of distilled water in the trunk) and hope to fix it this weekend. Am looking for ideas on how best to do so. Have thought of using epoxy to permanently glue the elbow into the radiator and of using the valve stem idea mentioned above. Any ideas? Pros and cons?

Thx,