Some of these old threads are worth their weight in gold!
I'm no great mechanic, but from the straightforward instructions I found in this and related postings on fuel senders, I was able to correctly diagnose and repair my car. I figure it saved me a few hundred bucks; but more importantly, I feel GREAT that I pulled it off (without blowing up the house!!!)
In my case, the problem was varnish deposits and a broken copper wire (the one that carries the "empty" signal to the indicator light on the dash). By CAREFULLY cleaning the device as instructed and then resoldering the broken copper wire back in place, the problems were eliminated.) I got everything back in place with the proper torque, and voila...
This archive is a tremendous resource to Benz owners. Thanks to all of you who share your knowledge and experience so generously. It's really appreciated by those of us that love these cars but lack the same level of expertise!!!