I found on Ebay "3.5mm Diesel Fuel Injector Return Line Hose 1 m" and then locally (autozone) hunted down the spring clips that you squeeze with pliers & release once in place. Used these on my 6635SXT and no leaks anywhere now...it's been almost a year and still no leaks. My other thought was to use heat-shrink tube on the ends once in place. I think I did that in one of the spots and it also worked by squeezing the hose so it cannot loosen off the barb end. Good luck.