Fuel leak from center bolt of main fuel filter, 606 - PeachParts Mercedes-Benz Forum

Chris W. · #1 12-03-2009, 01:17 PM

I reckon the main fuel filter is similar on older 6-series diesels as well. I'm talking about the main cartridge type fuel filter. On my '95, this is the hollow "bolt" which one tightens to shut down the engine manually.

I changed the fuel filter at the last oil change about 6 weeks ago and soon noticed that I had fuel collecting on the top of the filter bracket, coming from that "bolt". I had put new O rings on the bolt, as they are included with a new filter.

The leak wasn't bad, but annoying due to the smell. No running issues. At the oil change this weekend, I decided to change the filter again on the chance that it was something bad with either the rubber sealing ring on the filter or the O rings on the bolt.

No joy, I have the same fuel leak going. It started as soon as I started the car and moved it out of the garage. It appears to be leaking right where the bolt protrudes from the filter bracket. Anyone seen this before? I have the thought that perhaps I've overtightned the filter... anyone know the torque spec for the "bolt"?

Rgds,
Chris W.
'95 E300D, 302K

McCool300TD · #2 12-03-2009, 01:36 PM

Hi

It might be that you need a new shut off bolt, any time had them leak before i just replaced them with the much cheaper bolt from a 210 but with this bolt you get no shut off facility.

Hope this helps

McCool300td

tbomachines · #3 12-03-2009, 01:57 PM

I found that just tightening the heck out of it stops the leak, had it a few times.

Olivier · #4 12-03-2009, 02:02 PM

This need to be hand tights "like wise" force. Don't need to turn the spanner like crazy.

TMAllison · #5 12-03-2009, 04:45 PM

The manual kill button has a couple of orings on it. They rarely get replaced.

Look in the EPC for the details.

JasonC · #6 01-21-2010, 08:24 AM

Anyone figure out the right torque on the fuel filter bolt. I have a 92 w124 and 98 W210 and they are the same set up. It would be great to know a torque setting. I’m always over tightening stuff.

mwoodland · #7 01-21-2010, 09:29 AM

Here is the link to the rebuild thread:
rebuild shut off valve

Here's my write-up on the repair:
My 95 E300 Diesel ( 124 body ) started leaking from the fuel shutoff within hours of purchase.. which brought me to this thread. Its a few years old, so I thought I'd update it with details of the rebuild.

Disassembly was already discussed. The only difference is that the knob broke off when I was prying it up. Ambient temp was ~20 and wind chill ~11 degrees F, so I'll have to replace that at some point.

The local Advance Auto had all of the metric O-Rings, but you have to tell them that there are trays of Dorman hardware in the back.. the young ones don't seem to know.

The small O-Ring on the threaded shutoff valve is 4mm X 8mm by 2mm thick.
The small O-Ring on the shutoff body is 8mm X 12mm X 2mm thick, and the
large O-Ring on the shutoff body is 10mm X 15mm X 2.5mm thick. All three were less than $3.00.

Assemble w/ fresh diesel fuel.. shouldn't be a problem finding that.. (once the filter falls off), and drive the roll pin back into place.

Don't lose the roll pin, as they don't carry that size at your friendly FLAPS.
If you bend it up on disassembly, and its too far gone to reuse, the FLAPS typically has a small assortment pack of "Hair Pin" type clips. I bought one, just in case, as it had a small pin that looked like it would work, but I got the original roll pin back in place.

The whole operation took about a half hour, and beats the heck out of the $35, or $88 the good guys sell them for, or the $100+ the stealership sells them for.

Enjoy yours.

b52rule · #8 12-31-2010, 04:20 PM

I replaced the three O rings even though the smallest O ring was split. It took about 30 min and no leaks!