capthowdy548 Posted August 11, 2009 Report Share Posted August 11, 2009 Planning on finally getting my A/C compressor installed today on my 1999 Monte Carlo 3100, but had a question on the oil used to lube the new o-rings. I read everywhere online to use a SAE 525 Mineral Oil, and not the PAG oil to lube the o-rings. So far, every auto parts store I have been to looks at me like I am retarded if I ask for this, and then they have no suggestions for what to use. I hate to ask a stupid question, but is this just mineral oil like I would get at a pharmacy? If not, what can be used? I'm replacing the compressor, dryer, orifice tube and any o-rings I run into along my journey. Then pulling a vacuum and recharging. Any suggestions would be greatly appreciated. Quote Link to comment Share on other sites More sharing options...
xtremerevolution Posted August 11, 2009 Report Share Posted August 11, 2009 I seriously doubt the oil you use will matter much at all. Hell, just get some Vaseline. Quote Link to comment Share on other sites More sharing options...
DavidHowell3633 Posted August 12, 2009 Report Share Posted August 12, 2009 try looking at aircondition.com if you are heavy into learning about ac systems. I lived there a few years back and found, as I can best recall, that there are orings to match the type refrigerant and oil that is compatible with refrigerant. I got paranoid with all the details not wanting to ruin expensive machinery as I was converting my Mercedes from R12 to 134A. Now, I've converted a Jeep and goosed up three Cutlass Supremes that had dead AC systems. They are all doing well. After learning and following all the recommendations, I believe most shops don't give a rats arse. They evacuate and pull a vacuum, but almost never replace the filter/dryer or accumulator. They almost never convert the R12 compatible orings to R134A compatible rings. But, that's just my experience. If you want it done right, and want peace of mind, learn what you can and do it yourself. Other than that, find a trustworthy soul and bring your wallet. Quote Link to comment Share on other sites More sharing options...
1990lumina Posted August 12, 2009 Report Share Posted August 12, 2009 Any conversions we've done at the shop have had minimal parts replaced and zero issues. Quote Link to comment Share on other sites More sharing options...
capthowdy548 Posted August 12, 2009 Author Report Share Posted August 12, 2009 Well, completed the install last night. I vacuumed it for 45 minutes and it held at 30 for 10 minutes after I stopped, so I have my fingers crossed it will not leak. I just ended up using a bit of the PAG oil on each one...I called a local shop and he said it should be fine. Thanks for the suggestions, I really didn't want to do a shotty job and have to redo it next year, but I found it wasn't nearly as intimidating as the service manual makes it appear to be...next project, possibly LIM gasket. Quote Link to comment Share on other sites More sharing options...
DavidHowell3633 Posted October 7, 2009 Report Share Posted October 7, 2009 Hey, I've done that one on two cars so lemme know if you need any help. Others have written up good stuff on the process and the torque procedure was updated for the Felpro's so watch out for that. Quote Link to comment Share on other sites More sharing options...
carkhz316 Posted October 7, 2009 Report Share Posted October 7, 2009 Ya, use the Pag oil. It's gonna touch the seals when it's all closed up anyway. Mineral oil????? Never heard that one. Between Ester Oil and Pag oil, one is 12 or 134a specific, and the other one can be used on either system; with the Pag being the universal one I think. Quote Link to comment Share on other sites More sharing options...
Hairdo12 Posted October 8, 2009 Report Share Posted October 8, 2009 Ya, use the Pag oil. It's gonna touch the seals when it's all closed up anyway. Mineral oil????? Never heard that one. Between Ester Oil and Pag oil, one is 12 or 134a specific, and the other one can be used on either system; with the Pag being the universal one I think. Mineral oil is R-12 specific, Ester Oil is 134a but is compatible with residue from R-12 mineral oil. Pag oil is 134a only. Quote Link to comment Share on other sites More sharing options...
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