Nozzle question
 

I've got a question regarding the joint that is soldered/brazed between the threads and the tube that delivers the methanol to the combustion chamber. I have an injector that seems to be missing its brazing altogether and a couple that are pitted with "holes" in the solder. Is the brazing critical to the function of the injector? Can you break out a torch and run a new bead of solder yourself? Don't want to have a tube slide down into the combustion chamber. Thanks in advance.