Hello All,
I am getting myself confused with a leak I have on one of my metal IP lines. The car is an 87 300SDL; the leak is coming from the IP side of the metal fuel line. It is leaking from where the line goes through the nut part. When this happened on another line in the same car I just ordered a whole new line and replaced the whole thing. But today when I noticed this leak I looked at a schematic and noticed that there may be an O-Ring I can replace instead of the whole line. The schematic says that there is an injection pump pressure valve O-Ring and it has it placed between where the IP is and where the hose would go.

The basic question is: do I have to replace the whole line or can I just replace an O-Ring to stop the leak.

Thanks,
Matt

__________________
KI6CCA

Current Stable:
1987 300SDL
1980 450SEL

Out to Pasture:
1982 300D KIA (Rice Rocket vs. 123: He hit me at 80-100MPH I walked away he went to the hospital. Sounds fair to me!)
1985 300D EURO Scrapped (got more money from state than car was worth)
1979 & 1980 300SD Great Cars!

If the O-ring is suspect replace it.. If it still leaks then perhaps you threaded it wrong.

So there is an o-ring in there and not just metal on metal? The problem is not with the threading; it has never been replaced.

__________________
KI6CCA

Current Stable:
1987 300SDL
1980 450SEL

Out to Pasture:
1982 300D KIA (Rice Rocket vs. 123: He hit me at 80-100MPH I walked away he went to the hospital. Sounds fair to me!)
1985 300D EURO Scrapped (got more money from state than car was worth)
1979 & 1980 300SD Great Cars!

sorry I misread your post
I thought you said their was one..Im a 617 guy so im basing it on my knowledge... On the 617 their is no crush washer on the metal line where it threads to the IP delivery valves. Im sure someone that is 60X savey will chime in sooon

Yeah; I didnt think there was anything in there either but I wanted to make sure before I bought a $40-$50 part instead of a $0.50 part.

__________________
KI6CCA

Current Stable:
1987 300SDL
1980 450SEL

Out to Pasture:
1982 300D KIA (Rice Rocket vs. 123: He hit me at 80-100MPH I walked away he went to the hospital. Sounds fair to me!)
1985 300D EURO Scrapped (got more money from state than car was worth)
1979 & 1980 300SD Great Cars!

There is no o-ring between the hard line and the injection pump. These lines do crack after 20 years and there's a good chance that your problem is a cracked line. If you remove the line, you'll know immediately.

However, if the line is OK, your leak may be just below the connection to the IP........that's the delivery valve o-ring that's leaking. They do tend to develop some leaks now that the new fuel is out and there's a specific procedure to change the o-ring and copper washer. It's not the simplest of procedures and sometimes the o-ring fails to seat properly.

Steel Injector lines OM603.961
OM603.961 Steel Injector lines






Have a great day.

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ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
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Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

Any time you play with steel bolts or nuts and aluminum holes, be very careful. It doesn't matter if its on a fan clutch, a head, a thermostat housing,or a fuel injector delivery valve. THREAD BY HAND, BY HAND, BY HAND, UNTIL YOU CAN THREAD BY HAND NO MORE. Then torque appropriately. Respectfully submitted.

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2009 E320 Bluetec 117,000
1995 E300D 306,000 Sold
1996 Ford Taurus LX 130,000 Sold
1985 300TD Still 225,000 Sold
2016 Ford Fusion 24,900