After moving from diesel to gas and back I now find that my diesel requires DEF (my last diesel, a 2006, did not). I have not found a way to add DEF using the nozzles provided with the product without having fluid leak out through the little rubber vent at the nozzle. I can't believe everyone puts up with this so I must be doing something wrong. For now I am transferring to another container and then adding to the truck. Any tips, suggestions?