I occasionally need to inject glue in hard-to-reach places. My solution is a disposable syringe with a flexible extension. The syringe is a standard 10 ml plastic syringe, and the extension is quarter-inch OD 0.032-inch wall O temper 3003 versatube. The soft aluminum crimps perfectly over the end of the syringe—no leaks, no matter how hard I push on the plunger (which is pretty hard when I am trying to force thick structural adhesive through a long extension). The crimper is an Eightwood Coax cable crimper model 336G. The crimper and syringes are both available on Amazon. It is a nice quality tool and is what you will use to crimp coax fittings for antennas as well. No reason other size syringes/tubing could not be used for different applications—you could even put AN fittings on the end of the extension tube for bleeding brake lines, etc.
