Fuel Leak

[OffroadSpike]

Is the jeep hard to start after 24h with the engine off? If so air may be leaking into your hoses and diesel leaking out of them. Inspect the 3 hoses on the engine before starting it, see if there's any bubbles around hose ends. The orings there fail and may be leaking diesel out. I replaced my 3 hoses and fixed the hard to start ptoblems I was having. Other common problems as previously mentioned is the high pressure pump rubber seals, they sell a rebuild kit for it.

[Deezelweazel]

When you disassemble the fuel lines- check the colour of the O-rings being used to seal the fuel lines.

Black:
NBR Rubber used before Diesel blending.
Sadly many spare part hoses still come with the black O-Rings. Even the new ones from Mercedes! You need to exchange them!

Green:
FKM, also known as Viton made for blended fuels.
Mercedes introduced them, when They found out the problem with leaking fuel lines.

Layback is absolutely correct with his statement!
You can get the green ones at any Mercedes dealer. It is a good procedure to change them, when you change the fuel filter anyway.

When installing the fresh O-Rings make sure to lift them into position- if you roll them into the groove, the next leakage is pre-programmed.

[JoergM]

Originally Posted by Deezelweazel

When you disassemble the fuel lines- check the colour of the O-rings being used to seal the fuel lines.

Black:
NBR Rubber used before Diesel blending.
Sadly many spare part hoses still come with the black O-Rings. Even the new ones from Mercedes! You need to exchange them!

Green:
FKM, also known as Viton made for blended fuels.
Mercedes introduced them, when They found out the problem with leaking fuel lines.

Layback is absolutely correct with his statement!
You can get the green ones at any Mercedes dealer. It is a good procedure to change them, when you change the fuel filter anyway.

When installing the fresh O-Rings make sure to lift them into position- if you roll them into the groove, the next leakage is pre-programmed.

Thanks for the info. I just got a new set of O-rings for the fuel line from Europe and they are genuine MB and green so I guess I am safe here.

After the comment with the cheap fuel, I stopped fuelling up at this servo I was using for the last 1 or 2 months. Just one refill at my regular servo already seem to put a stop on the leak. Will work thru the exchange of the O-rings sooner or later anyway.

Thanks again for the tips.

[JoergM]

Originally Posted by OffroadSpike

Is the jeep hard to start after 24h with the engine off? If so air may be leaking into your hoses and diesel leaking out of them. Inspect the 3 hoses on the engine before starting it, see if there's any bubbles around hose ends. The orings there fail and may be leaking diesel out. I replaced my 3 hoses and fixed the hard to start ptoblems I was having. Other common problems as previously mentioned is the high pressure pump rubber seals, they sell a rebuild kit for it.

No, I have no trouble starting the Jeep. I had this when it was standing around for a couple of weeks without driving. I just had a wet oil pan and diesel smell everywhere underneath. After changing the servo it seem to get better already and the pan is drying.

[Deezelweazel]

When you get cheap fuel over here in europe, we talk about: roo fuel. Because that's the performance you get,- hopping around like a roo...

with the same side effects, lacking on additives, foaming like hell during filling-up and
lot's of leakage....

[JoergM]

Originally Posted by JeanLuke

The seal on the HP fuel pump is prone to intermittent leaking. There is a dribble hole that drops the diesel directly onto the serpentine belt. When mine leaked, the first symptom was the power steering stopped working from belt slippage. Mine only leaked cold, never hot.

Although I have changed the o-rings on my fuel lines (not yet all put together, was battling the crankshaft sensor and now the upper screw of the starter engine) I wonder what might be wrong if the engine still drips fuel.

I looked at new high pressure pumps but my gosh, they are expensive. By installing a new pump, I would double the value of the car instantly. So I was looking at some rebuild kits I can get from Europe via eBay. The part number is F01M101455 (https://www.ebay.com.au/itm/255291438495), it contains all the seals and o-rings required however. BUT it says that it does not come with the shaft seal. Does anyone know if this is a seal I do not necessarily need? Knowing my luck and if this is still leaking, I guess it is exactly the seal I need but wanted to confirm.

[JeanLuke]

The shaft seal is, from memory, to keep engine oil in the engine. If it's not leaking oil you shouldn't need to replace it.

I went down the path you are walking right now. After several tries, I bought a reconditioned pump from Hi Tech Diesel in Adelaide.

Your other option, if you can afford to have it off the road for a few days is to remove your pump and take it to someone like Diesel Australia for an overhaul. The reason I mentioned them is I know they can bench test the pump. Whomever you use, make sure they bench test it. I also know Hi Tech can, too.

EDIT: That reminds me. I still have the old one. It needs an overhaul. It has a suspected dead valve pack and I am not sure what else is wrong. You can have it for a slab.