I saw the R-134a conversion statement in the first post. It does not make a bit of difference in my opinion for the need or not for oil.

I hope your compressor does not start spitting out debris from the oil incompatibilities of R-12 to R-134a. Whoever did the conversion I hope they flushed the system really good as well as have a streak of good luck. Not to mention I am not 100% sure the stock 1990 hoses are barrier type. Otherwise the R-134a molecules tend to leak out at a pretty good rate.

Don't get me wrong, I am not a doom and gloom person. I've seen too many R-134a conversions go bad. I sincerely hope yours works out for you long term.

 

5.0L Situation where R134a AC system needs additional PAG oil ounces



R134a approximate low amd high side pressure readings using AC gauges, dependant on ur ambient temperature

[QUOTE=subford;8965530]Here is the TSB rla2005 was talking about.

Attachment 24460



Thanks for chart regarding PAG oil required