1995 E300 Diesel shut off valve "weep"
 

Hi there. I hope someone can help me with this. I did a search for leaky shut off valves (atop the fuel filter assembly) and couldn't find answers to me specific problem. I just replaced my fuel filter and both the orings on the valve assembly and still have this persistent "weep" right under the "cap" of the shut off valve itself. After the car sits or even after it is driven, a small amount of fuel collects right on top of the 19mm "nut" portion of the assembly. In other words, the fuel seems to be leaking underneath the cap, or around the portion of the assembly which screws/turns into the assembly when you turn the valve to "stop". This leads me to believe that there might be a third internal oring which is ordinarily not replaced in normal service and my fuel is slowly getting around it to cause the leak. Either that or the new ultra-low sulfur fuel has different properties from which the valve was originally designed. Anyway, I was wondering if anyone ever experienced a similar problem and if you tried replacing the whole assembly. It is part # 601 070 05 46 and is about $90, so I'm loathe to replace it if it in fact doesn't do the trick and there is something else I should try. Then again, I'm thinking that maybe the part has been updated to reflect the different fuels of today so that might also be a help. Thx.

See post #5.

http://www.peachparts.com/shopforum/diesel-discussion/174374-rebuild-shut-off-valve.html?highlight=shutoff+valve

Dont get confused with the discussion by 97-99's owners confusing their electrohydraulic IP "shutoff valve" with your kill/stop switch on the 95-96 N/A OM606.

I had to reuse the old oil filter O ring , since the Carquest one ( made in Poland) was too loose. Could it be that the new filter set had mis-sized o rings? My oil filter set did.

thanks TMAllison
 

As usual, TMAllison is right on the money. I ordered a new valve and after I get the old one out I am going to see what I can do about rebuilding it for fun / to have a spare. I figured the cap was press-fit into place. I'm not sure about all that drilling (described in post #5) though. We'll see. I'm surprised the internal o-rings aren't held in place by another smaller nut ala most 'faucets' I've seen (thereby facilitating easier rebuilds).

Also just replaced stop valve
 

Yes, keep us posted as to what you end up doing. Mine also cost $90 from the dealer, and I will do what you tell me to do, to rebuild my old stop valve to use for my father's car (which also has the slight diesel weep). Thanks, Dave

DIY steps
 

If you look above to the second post and click on the thread link which TM Allison provided, post #5 of THAT thread explains how to rebuilt the shut off valve. As I said, I MAY attempt it. I also may not since I think the process of screwing around with the thing AND going to my local hardware store to try and find a suitably-sized oring or two will take at least 1-1.5 hours and, at that 'expense', I'm probably just better off buying a new factory part for $100. Now that we are running ULSD everywhere, I imagine the new part will last for some time.

$
 

BTW, I got the part from www.benzbin.com and when I ordered it, it was $88.95. Today I checked the part price again and it just went up to $91.95. I saved 3 bucks! Woo hoo!

oops
 

Actually its www.thebenzbin.com