Fuel Leak near injection pump - PeachParts Mercedes-Benz Forum

agood · #1 04-14-2011, 10:44 AM

My 95 E300D has a fuel leak somewhere around the injection pump. I have cleaned it off with brake clean, and tried to located the leak from under the car, (since I can't see the pump from the top). But I can't pin point it. Is there a common place for these pump to leak? I'm hoping it is just a loose fitting.

TMAllison · #2 04-14-2011, 11:37 AM

Try a mirror and flashlight from up top after its cleaned again.

Most common points of leaks are at the prefilter, fuel line orings, SOV oring and DV's.

jbach36 · #3 04-14-2011, 01:16 PM

If it's around the pump, it might be from the O-rings, but then it'd be seen running down the pump a bit. I think I did a write up and posted it on the DIY area of this forum. If you don't see it there, email me, and I'll tell ya how to do it.

Check any of the rubber hoses that lead from line to line, they're easy to change.

jeff 1991 300d 159k

agood · #4 04-14-2011, 02:10 PM

Thanks for the info. I'm new to benz diesels.....so what are SOVs and DVs?

engatwork · #5 04-14-2011, 02:25 PM

Pull the intake manifold off and see if you can tell if it a delivery valve seal. If it is then follow the procedure for changing them out. Pretty common issue on these.

agood · #6 04-14-2011, 02:35 PM

OK, I assume there is a DIY write up somewhere on how to do this...???

agood · #7 04-14-2011, 02:38 PM

Ok, I think I found it....is this the right one

http://www.peachparts.com/Wikka/OM606DeliveryValveSeals

agood · #8 04-14-2011, 03:04 PM

Where do I find the tool needed to remove these valves?

pimpernell · #9 04-14-2011, 03:19 PM

Quote:

Originally Posted by agood

Where do I find the tool needed to remove these valves?

El Paso tools. Make sure you get the socket for your model vehicle.

http://shop.ebay.com/i.html?_kw=mercedes&_kw=valve&_kw=tool

TMAllison · #10 04-14-2011, 05:39 PM

First confirm whats leaking.

DV=Delivery valves
SOV= shut off valve. You prob don't have one on yours since its a 95

agood · #11 06-15-2011, 04:02 PM

OK, finally got around to looking at this...and it is not the delivery valves that are leaking. The top of the pump is dry....so something else on the pump itself is leaking.....ideas?

The weird part is I had the car on the lift for an hour with it running and never saw the leak, but left it there over night (turned off) and the next morning there was a big spot on the floor.
Is there something that leaks only when the motor is not running?

TMAllison · #12 06-15-2011, 04:36 PM

If it's "on the IP" and not the DVs', it has to be one of the fuel line orings connecting to the SOV or Lift pump, or the oring between the SOV and IP. I'd guesss the latter as they don't get changed until the SOV fails.

Ought to be able to feel the wetness. Loosen the windsheild washer bottle and mosve it out of the way so you can reach under the intake.

Diesel911 · #13 06-15-2011, 07:01 PM

Quote:

Originally Posted by agood

Thanks for the info. I'm new to benz diesels.....so what are SOVs and DVs?

SOV+ Shutoff Valve
DV= Delivery Valve (some of the mercedes service manuals call them Pipes).

agood · #14 06-16-2011, 09:03 AM

Quote:

Originally Posted by TMAllison

First confirm whats leaking.

DV=Delivery valves
SOV= shut off valve. You prob don't have one on yours since its a 95

OK, So I assume the delivery valves are on the top of the IP and are the ones mentioned in the DIY I posted above. If so, these are not leaking.....I can see them and it is dry all around them.

Now, Do I actually have an SOV, the quote above seems to question that.

pimpernell · #15 06-16-2011, 09:23 AM

Quote:

Originally Posted by agood

OK, So I assume the delivery valves are on the top of the IP and are the ones mentioned in the DIY I posted above. If so, these are not leaking.....I can see them and it is dry all around them.

Now, Do I actually have an SOV, the quote above seems to question that.

I am not questioning your eyesight, just relating my experience with the same issue. I had a leak similar to yours, and a small pool of diesel fuel show up in the belly pan of my car. Looking at the delivery valves on top of the IP, I could see no wetness whatsoever. Another poster suggested that I spray the top of the IP with carb cleaner, and wipe it totally dry, then start the engine, and keep running your finger along the top of the IP. Sure enough, after a minute or two, I could feel the diesel fuel on my finger even though I could not see any wetness with the naked eye. Changed out the seals, and that was the end of my leak. Good luck..