Fuel Filter Bolt O-Ring Question
 

Below is a pic of the bolt for the main fuel filter on my 95 E300D (although several cars use this same bolt). It is part no. 604 990 00 63. If you look carefully at the pic (sorry, it's a tad blurry), the large o-ring is installed but there does not appear to be any place for the small o-ring. My 91 300D uses the same bolt and it has places for two o-rings.

Is this just an updated design for the bolt and that steel band above the threading takes the place of the o-ring? Or am I missing something?

Hard to say. I've owned 3 different late model years of MB diesels, and at least two aren't the same. Give a call to your local MB dealer parts counterman, and or PParts, and go from there..

Does the Filter for the Models that use that Bolt have an O-ring attached to it in the middle of the Filter?

There is at least one other type of these bolts. Your photo shows the "simpler" one which only has 1 O ring. The other type I know of has a plastic knob on top which you can screw in (controls an internal plunger I think) and it will shut the car off if your key does not shut the car off. The shut off type bolt has 2 O rings IIRC.

I had to replace my shutoff type bolt to the tune of $139 a few years ago, because I could not get it to stop leaking. I've since found a thread which says you can disassemble the bolt to replace in internal O ring. (not the O ring included with the filter)

Rgds,
Chris W.
'95 E300D, 396K

My goal is to replace the one currently on car, which has knob and is leaking. So this new one I got will work fine, right?

The fuel filter bolt on my '83 SD had fuel seeping around it. I did some seaching on here and other sites (mbsource and dg). I found that MB tried a redesign in '83 using 2 o-rings to cut down on a leaking problem. I'm not sure how long the bolt using 2 o-rings was used but found my '83 has this. I did find viton o-rings that fit properly in the red HELP items.

Yes, the new, non-knob bolt should work OK.

Rgds,
Chris W.

Now you've got me curious. I swapped out the the simple bolt for the leaking shut-off bolt. Trying to figure out how I would take the latter apart to replace the o-ring. Do you recall where you saw that thread?

So it looks like that shut-off valve bolt was only used in the 95, onlly in the 606.910....after that they went to simple bolt.

Simple bolt seems fine....but I must admit to being mildly nervous that, strictly speaking, I have the wrong bolt in there. What would/could the effect of that be?

I have the "wrong" (simple) bolt in my '95 E300 and there are no problems. I did go so far as to buy the "correct" shut-off style bolt but could never get it to work and went back to the "simple" bolt. I also built my own emergency shut-off based on the one used with the OM603 engine, which works great. (There's a DIY thread here somewhere for that mod.)

Jeremy

Post #5.


http://www.peachparts.com/shopforum/diesel-discussion/174374-rebuild-shut-off-valve.html#post1369452