Cell posted the same thing a few months ago.
http://www.peachparts.com/shopforum/diesel-discussion/307329-pinhole-leak-secondary-fuel-filter.html
This pretty much proves to me how important a proper fuel water separator should be installed in diesel engines. The fuel quality is hit and miss, and the potential of water is great. The shallow bowl of the stock MB fuel filter is worthless and could only hold so much water.
Using an aftermarket fuel filter setup like Stanadyne or Racor would help this situation.
Here is also a link to a fuel filter mod using a Baldwin filter that can be drained out periodically.
http://www.peachparts.com/shopforum/diesel-discussion/225004-lower-micron-fuel-filter-mod.html
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