Diesel fuel line path, part identification
Thread Starter
Junior Member
Joined: Oct 2008
Posts: 41
Likes: 1
E300DT
Diesel fuel line path, part identification
I still have an air bubble entry problem on my E300. I cleaned down all the lines running by the fuel filter and prefilter. I've been checking them periodically to accurately find which line has the problem.
In another post a link was given to me showing a flow path, here it is;
http://bp3.blogger.com/_p71v9ofBM6w/...h/fuelflow.JPG
I have just found that the number 1 line is wet around the block coming from the engine going to the prefilter. Previously, and since I have owner the car I have seen nothing. I guess that it has just reached the point where it's now visible? Using the illustration's indicated direction of flow, and looking up a replacement line. Is the block where the number one line connects a thermostat?
The sites that I looked up the part, discribe the lines in order of fuel direction. So, this line I believe is the one referred to as "thermostat to prefilter (strainer)". Is this correct?
Please reply
Thanks
Lowflyingbird
In another post a link was given to me showing a flow path, here it is;
http://bp3.blogger.com/_p71v9ofBM6w/...h/fuelflow.JPG
I have just found that the number 1 line is wet around the block coming from the engine going to the prefilter. Previously, and since I have owner the car I have seen nothing. I guess that it has just reached the point where it's now visible? Using the illustration's indicated direction of flow, and looking up a replacement line. Is the block where the number one line connects a thermostat?
The sites that I looked up the part, discribe the lines in order of fuel direction. So, this line I believe is the one referred to as "thermostat to prefilter (strainer)". Is this correct?
Please reply
Thanks
Lowflyingbird
Super Member
Joined: Jun 2008
Posts: 835
Likes: 2
From: Bay Area, CA
09' E320
That is the fuel thermostat or pre-heater as others call it.
Heats the fuel when/if/as needed.
The short line connecting to the thermo is difficult to snap down in place and seal. Try removing it and reinstalling.
Push white horseshoe clip in tight, pull fuel line, examine oring, if oblong rather than round replace it, pull white clip back out so is loose and floopy, put fuel line in place, use 12" screwdrriver on top of line to get better leverage and push/lever down until you hear or feel TWO clicks. If that doesnt do it try putting some silicone grease on the oring and seating it again.
http://bp3.blogger.com/_p71v9ofBM6w/...h/fuelflow.JPG
Heats the fuel when/if/as needed.
The short line connecting to the thermo is difficult to snap down in place and seal. Try removing it and reinstalling.
Push white horseshoe clip in tight, pull fuel line, examine oring, if oblong rather than round replace it, pull white clip back out so is loose and floopy, put fuel line in place, use 12" screwdrriver on top of line to get better leverage and push/lever down until you hear or feel TWO clicks. If that doesnt do it try putting some silicone grease on the oring and seating it again.
http://bp3.blogger.com/_p71v9ofBM6w/...h/fuelflow.JPG
Thread Starter
Junior Member
Joined: Oct 2008
Posts: 41
Likes: 1
E300DT
Going to buy a new line
Thankyou for your help, but I'm going to buy a new line for it. Several of the other lines had been replaced before I bought the car. This line looks old and is yellowing from age. I do really appreciate the info on it's installation. It looked like it might be a PITA on that thermostat block.
Hopefully all goes well,
Thank you again
Lowflyingbird
Hopefully all goes well,
Thank you again
Lowflyingbird
Super Member
Joined: Jun 2008
Posts: 835
Likes: 2
From: Bay Area, CA
09' E320
New clear lines are nice to have, especially when new to you and you are tracking issues down.
In the future you might want to get some viton orings. They hold up better/longer. MB uses buna rubber. I helped a fellow from another forum with the sizes and he's put a kit together for the 606. See fryerpower.com
I have no affiliation.
In the future you might want to get some viton orings. They hold up better/longer. MB uses buna rubber. I helped a fellow from another forum with the sizes and he's put a kit together for the 606. See fryerpower.com
I have no affiliation.
Thread Starter
Junior Member
Joined: Oct 2008
Posts: 41
Likes: 1
E300DT
O rings
I have a few boxes of O rings. I'm not sure if any of them are viton, but I believe I have a set of HBNR which are green. I re-oringed the strainer side of that line and the main filter bolt, It made a little difference. I guess there was another bad seal somewhere.
The HBNR rings are primarily for air conditioning, but I've been told they hold up to alot of conditions.
Lowflyingbird
The HBNR rings are primarily for air conditioning, but I've been told they hold up to alot of conditions.
Lowflyingbird
Super Member
Joined: Jun 2008
Posts: 835
Likes: 2
From: Bay Area, CA
09' E320
I have a few boxes of O rings. I'm not sure if any of them are viton, but I believe I have a set of HBNR which are green. I re-oringed the strainer side of that line and the main filter bolt, It made a little difference. I guess there was another bad seal somewhere.
The HBNR rings are primarily for air conditioning, but I've been told they hold up to alot of conditions.
Lowflyingbird
The HBNR rings are primarily for air conditioning, but I've been told they hold up to alot of conditions.
Lowflyingbird
