Jeep CRD (270 cdi) fuel pump leak??

[Allthegear..]

Hi all,

I've got a strangely intermittent diesel leak on a Jeep Grand Cherokee 2.7 CRD (believe it's the same engine as an ML270 CDI). Essentially engine had Black Death which I fixed and engine was running sweet with no leaks or smells. Drove it around for a week until Saturday morning when it decided to gush diesel out like it was going out of fashion - 5-6 simultaneous almost constant drops coming from the high pressure fuel pump (Bosch unit with 748 CN7 stamped on the casing). Left it overnight and started it this morning and there appears to be little to no diesel leaking?? How can this be? Does the HP pump need the seals replacing or is there another common issue that could cause this? Any help always greatly appreciated!

 

[panason1c]

I had a similar problem some time ago when my HP pump would leak when the engine was cold but the leak would stop as the engine warmed up, I fitted a seal kit which stopped the leak for a few weeks but then it started leaking again.... a new replacement pump resolved the problem.

Dont waste your time and money on trying to fix your pump with new seals, it seems that the 'cylinder heads' on the pump can distort and cause the leakage and a replacement pump is the only long term fix.
I got mine from Eurocarparts and 3 years on it is still good.

 

[DSB SL AMG]

I had similar on S320cdi a few years ago...again I wasted money on seal kits but ended up buying a new pump which resolved all issues....

 

[simonafloat]

I had a similar problem some time ago when my HP pump would leak when the engine was cold but the leak would stop as the engine warmed up, I fitted a seal kit which stopped the leak for a few weeks but then it started leaking again.... a new replacement pump resolved the problem.

Dont waste your time and money on trying to fix your pump with new seals, it seems that the 'cylinder heads' on the pump can distort and cause the leakage and a replacement pump is the only long term fix.
I got mine from Eurocarparts and 3 years on it is still good.

...Agreed, we've just wasted our money on trying to fix ours with new seals. It's not as bad as before but still leaking, plus I think some air's finding its way in now. Looks like a recon unit is required!

 

[mersum1es]

I made successful repair myself. I think it depends which seal is actually leaking...

 

[Jane270ML]

This may help... High Pressure Diesel Injector Pump Seal Replacement - Mercedes-Benz Owners' Forums
or scare the s**t out of you!

 

[simonafloat]

This may help... High Pressure Diesel Injector Pump Seal Replacement - Mercedes-Benz Owners' Forums
or scare the s**t out of you!

I saw that, very tempted to have a go but I don't have a nice dry, warm workshop and its rained every day here since autumn... More inclined to buy the recon and get my local mechanic to install it.

 

[joesoap]

Are you sure its coming from pump?
Reason I ask is that the plastic fuel hoses have O rings in them and 2 of those pipes attach to the pump it could be running from there?