Took rubber hoses off of the intake and the return diesel lines , to replace with new lines but didn't put them on for another day or two and NOW I don't know which one is the RETURN and which one is the FEED LINE.

Tried putting a squeeze bulb from a outboard boat tank and was able to draw diesel fuel from both lines. Thought that the return line would just be air, but I am drawing diesel fuel from both lines.

Is the upper line return fuel and the lower line feed????

Thanks for your help.

Dave

Upper should be return, yes. I'm not 100% sure on this car, but in most applications, the return goes into the top of the fuel tank, while the suction comes out of the bottom.

Hope that helps some...good luck!

That reminds me; I need to replace the rubber hoses back by my tank...

I just replaced my return lines on my 82 240D and they went on the lower side of the injector. Those short little fuel lines are spendy little suckers---$15.00 for 6", but they'll last longer and not become brittle in the next two yrs.

Typically, but it helps to know what car you're talking about.

Sixto
91 300SE
87 300SDL
83 300SD