Fuel trickling out of air bleed hole?
 

Hello All,

I own a 1995 E300D.

For whatever reason, diesel fuel always seems to be dripping out of the air bleed hole (the hole that is visible at the top of the bolt that is used to secure the spin-on fuel filter) whenever the engine is running.

I have replaced the spin-on filter, & also replaced both o-rings that are on this air bleed bolt ( a few times) - but it did not help.
I have tried tightening the bolt to extreme levels, but did not help either.
I tried even tried greasing the o-rings.

Now I am thinking since the fuel is coming out of this air bleed hole, that this leak has nothing to do with any o-rings or connector or filter...but maybe I need to buy a new air bleed bolt?

With the engine running, I can see a fuel being expelled from the air bleed hole at a constant very slow rate (maybe 1 drop per second).
I have ignored it for years, since the car runs great - but the area around & under the bleeder bolt is constantly wet, thus leaving a wet path to the floor.

I searched thru hundreds of posts - but nobody seems to have this issue?
Anyone experience this problem (assuming it is a problem)?
Any suggestions?

I have a '97 E300D. I just replaced my spin on filter. I believe the bolt you speak of is called a banjo bolt. My filter came with two o-rings for this bolt, but my car only needs one of the o-rings so the other was thrown away. You should carefully inspect the condition of the oring at the bolt and the inner & outer (especially the inner) rubber gaskets on the spin-on filter.

You may want to purchase another spin-on filter and make sure you're getting the right part.

You should not need to tighten too much at all; overtightening can cause leaks. I tightened just enough to stop the leaking after I installed my new filter. Also, be sure to lubricate the outer gasket of the spin-on filter (just like you do for an oil filter).

I can speak only of a 616, 617 fuel filter, on one of them I needed a washer on the bolt itself, came with filter ordered from **************.com. Did not come with filters ordered elesewhere. In apinch I went to my local hardware store, and got a composite washer, works fine.

Picture please
 

Picture please. :)