AC O-ring Lube Type?

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2fine69s

2fine69s

69 340-6pak Rag Top
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Hey guys,
I'm installing a Classic Auto Air kit on my 69 Dart. The instructions say to use mineral oil on the o-rings. I thought that 134a refrigerant would not work with mineral oil. You guys have more experience in AC stuff than I do, so what do I need to lube the o-rings when putting the hoses together?
 
I use whatever oil I am using in the system to lube the o rings.
 
R134a systems usually require PAG oil. However, if ur retrofitting it to an original compressor I would use what the compressor calls for.
 
Never use PAG oil in a system that has had R12 and mineral oil in it only use POE oil. So for retro fitting POE is the correct oil to use.

Brian
 
RustyRatRod said:
I use whatever oil I am using in the system to lube the o rings.
Click to expand...

X2 when converting you should flush out as much of the old mineral oil as you can. Any remaining mineral oil will settle at a low point in the system and sit there. Use POE Ester oil if you are not totally flushing.
 
Hi,

The OP is talking about installing a Classic Air Retrofit system which is an R-134A system. Classic Air provides the compressor oil and I believe they use a PAG type. They are suggesting 525 mineral oil for the O rings only which is correct. An even better O ring lubricant/sealer is some stuff called Nylog. They have an R-134A specific type that works great in preventing leaks.

Using 525 mineral oil is okay since there is so little used to coat an O ring there is no oil interaction issues.
 
FIY...Before I retired I worked for a major AC remanufacture of compressors and my 1994 Duster was one of the companies "test mules" . One of our tests was to install a reman compressor on the Duster (134A system) using mineral oil, not the OEM PAG oil. Since the mineral oil would not mix with the 134A refrigerant it all remained in the compressor, where it belongs. The compressor is the only moving part in the AC system so that is where the oil needs to be. That compressor was nice and quiet as well as worked perfectly for as long as I owned the car. I sold it in 2005 still blowing ice cold air. All O-rings and seals need to be lubed when installed.
 
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