I'm in the process of replacing my expansion valve, accumulator/drier, and compressor on my 96 T/A. I bought all of the seals and 8 oz of double-ended PAG.

I was looking through my service manual (Helms) and noticed that it said (in several places) to lubricate the seals when replacing..which is expected. However, to my surprise, it stated not to use PAG, but mineral based oil. Why?


I can understand when retrofitting an R-12 system that was not designed for PAG (PAG is more corrosive to seals and hoses). But in an R-134a system, shouldn't the new seals be fully compatible with PAG? What's the issue? Is this the old line of thought back in 1996 when the manual was printed?

 

Lol, I don't know, but I would just do what it says.

 

If you can find it near you, use Nylog. Pretty heavily used in the AC industry; it's a seal lubricant/non hardening glaze.

 

Vaseline........

 

You can also use the DEC PAG oil to lube the O rings. Don't know why you couldn't.