Check the top of your secondary fuel filter. Is there any moisture (fuel) showing around the bolt. If so, there is a small o ring underneath that value which can be replaced (contrary to what MB tell you). Just drive out a tiny spring pin and replace with a paper clip later. I used a Harbour Freight seal which has been working fine for several months. MB wanted $200 for the entire valve. Anything else: stormwindalpacas.com dave