Which grease

On orings use silicon grease I got a small tube for a few bucks at Lowe’s in the plumbing department. For grease I use a copper aniti seize grease great for keeping screws and bolts from seizing especially when different metals are screwed together. I also used it on the internal parts of guns with all grease a little goes a long way too much will attract dirt.

https://www.amazon.com/Permatex-09128-Copper-Anti-Seize-Lubricant/dp/B000HBM8HU/ref=sr_1_sc_1?ie=UTF8&qid=1512602092&sr=8-1-spell&keywords=Copper+ani+seize+grease
 
Certainly NO M olly or other burn able lube inside any high pressure area.
Any lube is fine for exterior metal, pure silicone for anything that even might see air pressure.
\
75d050b663dc2c6f984a64814930207e.jpg


About $7.00 for 20 years worth.
John