As a B100 biodiesel user I naturally keep a close eye on my fuel filters and started to notice awhile ago that the primary in the '87 300D was looking strange. Today I decided to be safe and change it even though it has been on for less than a year and did not appear dirty. As you can see from the photos, the inside white plastic framework (holds the filter screen material) is warped, as if the biodiesel has softened the material of which it is made. I'm sure it was not that way when I installed it. The outer clear plastic part of the filter is undamaged and it did not leak.
I don't know the brand of the filter -- I tend to buy a few filters at a time as part of a larger order and don't know where this one came from. The only marks on the plastic are a directional arrow and a symbol that looks like a crown with three points (or a letter "W" in a box). Anyone recognize that?
The filter had only a little crud in it -- the black specks in picture #3 show the fuel from the filter, dumped into a cup. If the filter had not been internally melting I probably would have left it alone.
While changing the filter, I also discovered that the hose from the fuel heater to the lift pump was starting to melt and drip (at the lift pump end). The 4th picture compares the damaged end to new fuel hose. So I changed it too. Always a good idea to check everything once in a while and someday I'll learn to do that.
Let that be a lesson to you!
Jeremy
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"Buster" in the '95
Our all-Diesel family
1996 E300D (W210) . .343,000 miles
Wife's car
2005 E320 CDI . . 148,000 miles
My car
Santa Rosa population 177,300 (2026 projected)
Total. . . . . . . . . . . . 668,300
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970