I work with a fair amount of commercial and industrial equipment and I often see a very obvious and very effective solution.
Silicone. Pick your favorite color or brand! Works every time!
For high pressures two part epoxies do super too!
I have used JB weld on hydraulic fittings up to 5000 PSI peak pressure and never had a leak yet and some of those fitting are on constant use and have never leaked a drop in years. Plus if you do need to take a fitting apart it will let go and cleanup with a simple die grinder wire brush.
"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." -- Mark Twain