I don’t know the viscosity, but you can buy mineral oil at just about ANY drug store. (It turns number 2 into a number 1 no problem, but not as good as dissolving 2 tablespoons of Epsom salt in a glass of water and drinking it-just be in the bathroom when you drink, preferably sitting down already lol). I’ve used off the shelf mineral oil hundreds of times to lubricant orings. I wouldn’t hesitate to use it on A/C orings, but I’m not the expert. Hit your local Chevy dealer parts counter. There is no doubt in my mind that GM has some kind of A/C compressor assembly lube, and the parts guys there will know how and where to steer you.My factory service manual says use mineral oil of 525 viscosity to lub the O rings only on the AC.. Ive tried 3 car parts stores looking they all have NO mineral oil at all.. Any ideas?? thanks Mike
I knew a pro would step in and set the record straight.Any air conditioning oil will work. Do not use drug store mineral oil as it has moisture in it and that is death to ac systems. Are you using r12 or r134a? I ask because it will make a difference in how the system is charged.