Hi, I ordered the new-design replacement compressor for the '86; the GM A6 on my car has a locked-up pulley bearing, although the compressor itself will turn by hand. I do not know how much if any of the refrigerant is left in it.
Question: is a different expansion valve required to use R134-A, or are these changed for preventative reasons, or?
Thanks

 

I have recently changed both of the expansion valves in my Series 1 XJ's. If I was changing a compressor and going to R134, I would change the expansion valve now...yours is a lot easier
to change as it is exposed on the firewall - use two wrenches, one to hold and other to loosen....breaking off the tube would not be a good thing! Adjusting is done - assuming you cannot
purchase a valve that says "R134"...not likely for a Jaguar....

After reading articles about the subject, my very good AC guy said adjusting the screw works, so I adjusted per an article:

"Turn expansion valve screw CCW ¼ turn to adjust for R134 vs R12"... I turned mine a generous 1/4 turn = more....vent temps hover around 38-40F...

The evaporator in a Series 1 is not very efficient - Jag's first try at putting whole AC system inside the front of the car...but - it does work very well - except for the volume of air produced by the anemic S1 fans....