I was able to source new o-rings from dealer. Discussions range from R134a does not need special o-rings to it definitely does. I converted with "Envro-Safe" and used OEM seals about 3 years ago - it hasn't leaked yet. Don't forget to pull the evaporator for more seal replacement fun.

You can try this source for A/C parts and seals.
http://www.acsource.com/o-ringgasketassortments.aspx

He sells dryers for cheap as well.


92 Montero LS 3.0L V6 Auto, Stock, Original owner, 185,800K miles