Om648 fuel return lines - PeachParts Mercedes-Benz Forum

chronometers · #1 10-07-2018, 07:45 PM

What type of fuel line should be used to renew these lines? Are they easy to replace?

Older engines have barbs on the injectors. I thought the newer engines use o-rings to seal the injectors/hoses but they also have barbs going to the hoses. There are o-rings which seal the barb hosings to the actual injector.

I plan to use Viton hose as supplied by Will to replace the original hoses.

I noticed the return hoses are getting hard and after having to replace quite a bit of the fuel line going to and from the fuel pump and fuel filter on a trip cross country, I think it may make sense to replace these lines as well.

Here is a warning to other E320 CDI owners out there. These lines are potentially getting brittle. Don't let them strand you on the road.

Thanks!

chronometers · #2 10-12-2018, 04:18 PM

We decided to not do the install now as I am doing a long road trip and was afraid one of barbs would break. The two end connectors are metal but the four middle Ts are plastic.

I've read about the plastic Ts breaking.

Thoughts?

chronometers · #3 10-16-2018, 11:56 AM

Has anyone else replaced the fuel return lines on the OM648 or later OM642 with braided rubber line?

ROLLGUY · #4 10-16-2018, 10:21 PM

Quote:

Originally Posted by chronometers

Has anyone else replaced the fuel return lines on the OM648 or later OM642 with braided rubber line?

The only factory option is the complete return hose assembly, and it is hundreds of dollars. Some have metal "T"s others are plastic. The "T"s can be purchased on ebay. I bought a set for a 4 cyl, as I only needed one T. All the CDI engines (4 & 6, V and I) use the same parts. The hose is standard injector return hose. No reason why you could not use Viton.

chronometers · #5 10-19-2018, 10:39 AM

Thank you for the info. Did some of your plastic Ts break or become brittle?

ROLLGUY · #6 10-20-2018, 03:20 PM

Yes they did.