I am going to be adding an AC system to my 82 Ramcharger. The truck curently has no AC. I am adding a system pieced together from factory components and an aftermarket under dash evaporator and fan unit, a new crossflow condenser, new hoses and fittings and o-rings rated for R-134, new receiver dryer, new binary cutoff switch, and factory brackets and Sanden compressor.
My question is which oil I should use. The only oil in the system will be what is left in the compressor after I drain it. All other components will be new and dry, or old and dry in the case of the evaporator. The compressor is a Sanden unit of of an 83 Dodge van, so it was originally in an R12 system. I have read that ester oil is compatible with all oils and all refrigerants, but I have also read that compressor manufacturers prefer you to use oils specially designed for their compressor.
I am looking for a recommendation on what kind and how much oil I should put in the new system. My options are ester, PAG 46, or Sanden SP-15. See here:
https://coldhose.com/oils.html
I would think the Sanden oil would be best because I am using a Sanden compressor, but I won't be able to remove all traces of the original oil from the system, even though I will drain the compressor before charging the system. That makes me think I should just use ester since it is apparently compatible with everything.
Thoughts? Any AC experts in the house willing to share their knowledge with someone who knows nothing about refrigration systems other than I like them?
Thanks.