This is my injector before and after cleaning itAdMax should be great for what i heard. The external leak was only visible in situation which you will not encounter (manually forced regen - 3.000rpm....adblue activated....). A clear periodical mist was seen and heard comming out of injector body - where the holes are. No such case on a new inkector! There was no adblue residue (the mist dries in air) neither on the outher body nor on the inner nozzle itself. Just a small residue (1mm) of black stuff (soot) on the nozzle.