THX for replies!
I have used WD-40, vaseline, white, normal, lithium grease,many oils from my wifes cooking supplies,motor oil, high tech RC heli motor oil,mineral oil, parafin oil, generic bike oil, spray silicone,3 in 1, ect...
A close friend had some old white generic silicone grease, tested, working by far the best!
ALL of the other lubes worked for a short period of time, as IMHO reacted with CHEAP rubber used in most pumps, and got gummy, sticky, attracted sand and dirt becoming stiff.
Did see inside my latest pump buys a very thin clear lube used, again very cheap brands, anyone know what they use?
Just wonder if silicone grease or oil would be better?
I will also add I always use a good quality tape around top to cylinder threaded joint for added sand, dirt repulsion.