I would do a search on the W211 forum. I had a 211 wagon and the leak and did not read anything about the fuel pump stopping. The leak is via the gaskets on the top of the tank accessed via the back seat. Almost always when you fill the tank and bit leaks and you can smell the fumes (did not read about leaking fule on the ground). Some have replaced the gasket and some the entire sending unit.
Michael in Arizona
Michael in Arizona