W210 E300 fuel filters - how many?
 

I know the older diesels had a clear/smaller fuel filter in addition to the spin-on one. I'm not seeing that in any obvious place on my '98; did they eliminate it or is it somewhere nasty like under the manifold?

It's under the fuel inlet on the fuel filter housing. The filter is secured with the 10mm bolt on the left top of the housing. Remove the bolt and the little hold-down piece of metal and the fuel line should come out. then, pry upward on the flanged black plastic piece and the whole pre-filter will slide up and out of the main filter housing.

Don't forget to either re-use the O-ring from the old filter or get a new one as the new ones may not be supplied with one which will lead to difficult/impossible starting.

Here, a picture is worth a 1000 words...

http://i3.photobucket.com/albums/y71...fuelsystem.jpg

#47 and 50 are the hold-down hardware.
#26 is the pre-filter.
#29 is the infamous "missing" O-ring.

Listen to Evan! There have been way too many threads on this forum from folks who "threw the baby out with the bath water" (threw away the old pre-filter without removing the o-ring). Why Mercedes sells the o-ring separately is beyond me. If you contemplate ever using biodiesel, you can get a Viton o-ring for the pre-filter.

A recommendation that I have learned the hard way: when doing a project, keep all of the old "bad" parts until the car is back together and you're sure all is well. If the garbage is going out tomorrow, well too bad, it can wait a week.

Jeremy

Ahh, got it, that's different. The picture certainly helps! Side question - from where did that diagram originate? I appreciate good documentation. Is this the ~$200 factory manuals?

Looking on FastLane, I need this:
http://catalog.peachparts.com/item.wws?sku=W0133-1640591

which has a note as you mention:
Use with (1) 601 997 01 48 pre-filter seal ring.

which I assume is Fuel Filter Seal W0133-1643308 (would be nice to have the same p/n both places ;-) as seen at
http://catalog.peachparts.com/item.wws?sku=W0133-1643308
Is this correct? I assume so as the spin-on filters seem to come with the o-rings. Those must be 11 and 14 in the diagram.

As to Jeremy's biodiesel comment, I'm actually running B50 now and have been since January. Hence wanting to get the filters figured out, ordered, and delivered to me before I desludge the tank into them to the point of plugging :D No noticeable drop in performance yet but I'd rather not wait until that point. I'm going to order three sets upfront to allow for two filter changes.

Is this a good source for Viton? http://www.fryerpower.com/store/page14.html (ha, and they have the exact same fuel system diagram linked)

Both my picture and the one linked on JA Davis' Fryerpower.com were "stolen" from the Russians... :)

www.detali.ru

You can navigate or enter your VIN and see part numbers and diagrams for a variety of vehicles.

Yes, I got all my Viton o-rings and Viton return hose for the injectors from Fryerpower.

The diagram probably came from EPC, the Mercedes Electronic Parts Catalog here. A subscription is free for USA residents; they want a credit card number as proof you're a USA resident but the subscription is free (used to be $20/year). It's a great source of information and compliments the expensive DVD manual.

Jeremy

The diagram is from here:

http://www.detali.ru/cat/oem_mb1.asp?TP=1&F=210225&VIN=

Ha, triple post!

Fine minds think alike.

I just find it crazy that 3 people separated by thousands of miles are posting in the same thread with similar information within 1 minute of each other... And it's not like theres a multitude of 210 owners on here...

Oh, but we're so, so dedicated to our W210 TDs!

Ditto!

My server hicc-uped or this would have been right after you posted.

Haha, funny!

I'll look into EPC. It sounds like the Russian site may be derived from that?

Sounds like I only need Viton for the return line; the hard clear plastic lines are OK? How much return line do I need to order from fryerpower?

What's the usual expected life of rubber parts when exposed to bio in higher concentrations (B50-B100)? ie how long before I NEED to replace all, um, 23 o-rings that come in the kit? I know the fuel line o-rings at least are new; they were replaced just before I bought the car, but I doubt "new nitrile" gains me much of anything longterm against the solvent power of the bio. ;-)

-dd

Viton orings are said to be more fuel and bio resistant than the buna nitrile rubber MB continues to use. Is a slightly harder rubber compound. Who knows how long they will last? Mine ahve been in for about 3 years or so.....buna will also last at least a couple of years IMO. My DV orings remian Buna; I won't change them until they leak. Have been in for 3 years.

You'll ideally want about 48" of cloth braided or viton return line. Mine is cloth and is original FWIW and I have burned a fair amount of B99 previously, although not recently since it is not cost effective.

The Russian site is the EPC; I've never joined startek since it is there to use. From Russia, with Love.

No need to go nutty replacing fuel lines yet. Mine have seen 45k miles on my 97 on WVO/RUG blends and homemade BD. Not a leak yet.