(ML270 - W163) I have a leak on my rear injector and I can hear air coming from the fuel return line that sits on top of the injector.

[ants-uk]

Can someone please tell me possible causes and fixes. Perished seal? Replace the top return fuel line? Video below.

Also, can someone please name and tell me the function of this bolt (image attached) that sits underneath the fuel rail at the back. It has 3 holes at the bottom of the bolt and the return fuel line that sits on top of the injectors feeds into it, obviously the fuel rail feeds into it and then the line continues towards the fuel cooler. Do those three holes need to be aligned specially or can it just be tightened? I ask because the fuel leak from the rear injector is new and I'm thinking this might be one potential cause

Thank you in advance

Here is a video with sound

https://imgur.com/a/JmCSZRl

 

[M80]

The return 'leak off' connections often have an 'o' ring to seal. I'm assuming yours does.
After market replacements can be a bitch to fit if they're a bit larger, so MB genuine would be best.

The feed bolt doesn't need to align, the receiver allows for the fluid to pass regardless of orientation.
There are copper washers either side that create the seal on those. Again MB could supply, but I wouldn't be averse to measuring and sourcing elsewhere.

 

[ants-uk]

The return 'leak off' connections often have an 'o' ring to seal. I'm assuming yours does.
After market replacements can be a bitch to fit if they're a bit larger, so MB genuine would be best.

The feed bolt doesn't need to align, the receiver allows for the fluid to pass regardless of orientation.
There are copper washers either side that create the seal on those. Again MB could supply, but I wouldn't be averse to measuring and sourcing elsewhere.

Thank you for the reply. So you think it's just a simple seal replacement job? I guess do all of them while I'm there? Is it as simple as uncliping and pulling the thing out? Special tools?

Thank you again.

 

[M80]

Tbh my memory of your system is faded.
But as I remember don't they unclip and pull upward?
Warm the engine bay first as old plastic brittle clips break easily.

 

[ants-uk]

Tbh my memory of your system is faded.
But as I remember don't they unclip and pull upward?
Warm the engine bay first as old plastic brittle clips break easily.

Okay, I'll have a play with it.

I made a post about a perished rubber garter(?) on my transmission oil filler pipe. I was wondering if you could give the post a read and see if you can tell me what might be going on. I'm wondering whether transmission oil should be making its way up the pipe from the tray (one problem?) and whether it's an easy job to replace the rubber garter/seal/cover (second problem). So maybe more than one problem there?

Other post

Thanks for the info re the injector. I'll get it sorted.

 

[ants-uk]

Tbh my memory of your system is faded.
But as I remember don't they unclip and pull upward?
Warm the engine bay first as old plastic brittle clips break easily.

So MB don't supply the rings on their own. I would have to buy the leak off pipe and the seal come with that. £100+

I've been unable to source the rings while searching for ML270, OM612, W163 etc and the best I can do is this set. What do you think?

O-rings - Amazon

Also, what's the difference between green and black o-rings. Any difference in quality or usage?

Any help would be great. Thank you.

 

[M80]

I found a couple of possibilities,
maybe you compare / see which looks preferable.

Mercedes Sprinter 2.7 CDI Diesel Injector Leak off Connector Kit 5 Cylinder | eBay

Bosch Common Rail Diesel Injector Leak Off Kit. 1 x 1m Over Braided Leak Off Pipe. 1 x 90° L Shaped Connector. This kit fits all common rail engines with Bosch injectors starting with part number 0445 110.

www.ebay.co.uk

Mercedes Sprinter 2.7 CDI / Replacement Leak off Connector Seal for Bosch x 5 | eBay

5 x Viton Rubber Leak-Off Seals (Colour May Vary).

www.ebay.co.uk

FUEL INJECTOR LEAK OFF FUEL RETURN PIPE FITS MERCEDES-BENZ Sprinter 6020704732 | eBay

Find many great new & used options and get the best deals for FUEL INJECTOR LEAK OFF FUEL RETURN PIPE FITS MERCEDES-BENZ Sprinter 6020704732 at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

The last one has part number '602' so maybe for a different set up, as I'm guessing your engine is a '647' ??

 

[ants-uk]

I found a couple of possibilities,
maybe you compare / see which looks preferable.

Mercedes Sprinter 2.7 CDI Diesel Injector Leak off Connector Kit 5 Cylinder | eBay

Bosch Common Rail Diesel Injector Leak Off Kit. 1 x 1m Over Braided Leak Off Pipe. 1 x 90° L Shaped Connector. This kit fits all common rail engines with Bosch injectors starting with part number 0445 110.

www.ebay.co.uk

Mercedes Sprinter 2.7 CDI / Replacement Leak off Connector Seal for Bosch x 5 | eBay

5 x Viton Rubber Leak-Off Seals (Colour May Vary).

www.ebay.co.uk

FUEL INJECTOR LEAK OFF FUEL RETURN PIPE FITS MERCEDES-BENZ Sprinter 6020704732 | eBay

Find many great new & used options and get the best deals for FUEL INJECTOR LEAK OFF FUEL RETURN PIPE FITS MERCEDES-BENZ Sprinter 6020704732 at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

The last one has part number '602' so maybe for a different set up, as I'm guessing your engine is a '647' ??

That's great, thank you. Yes, the third one shows up as incompatible for my car.

I'll try the seals first and then could take it from there if they don't work.

I did actually search for sprinter but maybe my wording was wrong as it was coming up with a van lol

Thank you very much for your efforts. I'll try the o-rings and let you know what happens.

 

[ants-uk]

I found a couple of possibilities,
maybe you compare / see which looks preferable.

Mercedes Sprinter 2.7 CDI Diesel Injector Leak off Connector Kit 5 Cylinder | eBay

Bosch Common Rail Diesel Injector Leak Off Kit. 1 x 1m Over Braided Leak Off Pipe. 1 x 90° L Shaped Connector. This kit fits all common rail engines with Bosch injectors starting with part number 0445 110.

www.ebay.co.uk

Mercedes Sprinter 2.7 CDI / Replacement Leak off Connector Seal for Bosch x 5 | eBay

5 x Viton Rubber Leak-Off Seals (Colour May Vary).

www.ebay.co.uk

FUEL INJECTOR LEAK OFF FUEL RETURN PIPE FITS MERCEDES-BENZ Sprinter 6020704732 | eBay

Find many great new & used options and get the best deals for FUEL INJECTOR LEAK OFF FUEL RETURN PIPE FITS MERCEDES-BENZ Sprinter 6020704732 at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

The last one has part number '602' so maybe for a different set up, as I'm guessing your engine is a '647' ??

Leaks all sorted. The leak-off hose wasn't in the best of shape so I bought that little kit you mentioned and replaced the hose and the junctions. That was after first just trying the o-rings. The leak I thought was coming from trans oil filler was, as expected, fuel carrying over the bridge there.

MOT booked for next week. There will be a long list of things to do but I'm ready!!

Thanks for your help on all of this. Much appreciated.