1992 745 170K

I found a nice 740 wagon to replace my son's 1990 240.

I am almost ready to have him register it so I can do a few hundred miles of shake down driving before I turn it over to him.

The AC system has an odd conversion. There is no sticker on it to indicate it was converted to 134A. The fill fitting is on the side of the receiver dryer where the pressure switch was. The pressure switch plug has been jumped with a piece of wire.

The previous owner said the AC did not work and he was pretty sure that it was a leak in the condenser. I have encounter that before and the easiest way I have of determining if that is true or not is to simple shoot a little 134A into the system. If you are in a quiet environment you can sometimes hear the leak.

When I tried to connect the fill fitting on the receiver dryer to my 134A hose I find that the fill fitting is too large and I am unable to attach the hose.

Has anyone here ever encountered this before? I wonder if the "conversion" used one of those odd refrigerants that were fairly common a few years ago?

I assume that I will need to remove this fitting anyway so I can install a pressure switch, and remove the old R12 fitting to install a 134A fill fitting.

Randy