I've only used mine for a couple of months, probably front loader twice and backhoe 3 times. It started leaking today on every zerk I tried it on. I clean the zerks before greasing of course. I also tried cleaning the coupler head with solvent and compressed air - - still no good. Took the darn thing off and went back to a regular push-on head and that worked just fine to finish the grease job - no leaks.
I plan on calling them to see what they have to say and will do a follow on post here.
BTW, just a reminder, many regular grease coupling heads are adjustable, so you can loosen the head to make it easier to remove. On two zerks on my SSQC, the coupler is passed through a hole and then maybe goes another 6" to the zerk - i.e. not convenient to push it off to the side for uncoupling. I just wait a second for the grease pressure to drop, then pull it straight off with a bit of wiggling - no prob.
I to like the locknlube, it's for sure is a luxurious (if that word is even applicable to greasing!) way to do a messy job - quick, efficient, and nice while it lasted.
bumper