AC R134 Retrofit

There
has been a question recently on this topic-so I thought I’d actually
post this link along with some other info.
www.epa.gov/ozone/title6/609/retrguid.html It’s not an add! Just
updated info on whats needed or not needed to make it work. Sorry for just
giving a link-but I don’t think I could type all that info in here! I
waited until my compressor died, then did the swap. Basically followed the
epa.gov site’s recommendations along with the following; I used a
standard orifice tube, and then turned the low press. switch 1/4 turn
counter-clockwise. The low press. switch screw is found under the elec.
connector to the switch. Just look down inside after pulling off the
connector and you’ll see it. This helps with cycling/cooling at idle.
Some folk have used a VOV orifice also with good results. (variable
opening valve).I did change the hoses as they were old already and figured
they’d leak for sure. The condensor on our cars are a ”headered”
design instead of a con’t ”S” tube design. The headered design is
supposed to work best with 134; so I didn’t change it and it works
great. I added 8oz. total oil to the system, dividing it up between the
compressor,drier,evap. and condensor. I put 3oz. in the compressor-then be
sure to turn it over about 20 times after the hoses are hooked up to
prevent the oil from ”press. locking” when you first run it. The stock
R12 takes 2.25 lbs of R12, so go 80% of that for 134. Take the valve cores
out of the old R12 fittings before attaching the new 134 fittings. I think
that about covers it-good luck and good cooling!