What is the diameter, and how much fuel line would I need for the fuel return line in a 240d. Do I have to get the braided line or will any fuel line work. Do you have to relive the fuel presure or just pull the line off and replace it, How do you do it? Also how would you change the primary and secondary fuel filters, do you have to relive the presure?

 

The ones near the injectors. That go to the filter.