Re: 1985 300SD 5 Cyl.:
One of the return fuel lines between #3 and #4 injector sprang a leak. This is black plastic hose about 4 mm ID with a black fabric braided covering. It runs from the fuel filter to each of the injectors. Couldn't find it locally (Autozone had nothing like it), so I did a temp fix with black RTV. I ordered what was described as return fuel line from THEBENZBINS, and it had a wall thickness twice what is needed. (the nipple is really close to the injector body!). I need several feet of it, as it really all should be replaced. Thanks, Jim