hello larry,

the conversion in the 91-93 cars are very doable. i've done the conversion on my 86 (expansion valve type) and on my 92 (orifice type) using original volvo kits.

you have the orifice type which is cheaper. it is not a difficult job for the later models.

i bought my kit for my 92 from fcpgroton--$65+. i followed these instructions from a zip file on dave shannon's page--look near the bottom:
http://www.homestead.com/volvo2/quickindex.html

tons of other useful stuff w/ pics!

note that much of the ester oil goes in the accumulator. one difficulty is trying to get the old mineral oil out. since i replaced my compressor from the junkyard, i just poured the old stuff out of the replacement compressor.

maybe you can try to use a syrenge or something like that to get the oil out of the compressor.

i used my a/c compressor as the pump. i connected the clutch wire to the battery and let it run until nothing came out of the discharge port.

also, a lot of people mentioned a variable orifice tube. i used the one in the kit, but check these archives or write a post where to get one--supposed to be efficient at low rpms or something like that.

i believe that the low side should read between 25-35 psi. connect the gauge where the freon goes in.

final point. there is a low pressure switch on your accumulator designed for r12 pressures. pull an r134 pressostat off a late model 740, 940 in the junk yard. it's the only thing with wires attached to it on the accumulator.

you have short summers up there. i'm in the houston area, our cold fronts are when someone leaves the freezer door open.

a lot more help in the archives and bb's FAQ 7XX/9XX forum, which uses the same compressor and system.

regards,
byron golden
86 245
92 245

Well you can try a simple R12 recharge which will probably set you back most if not all of your 2 Benjies you have alloted for it or you can attempt your conversion. What all is included in this e-bay kit that you mentioned? If it is just a couple of change over valves and a bottle of oil I would think it would be much less than a hundred dollar bill. If it includes the evaporator and expansion valve then you are talking about a righteous deal there, providing the parts are good quality parts and not some chinese garbage.
You can rest assured that the gas leaked out. If it is not in the system then it had to go somewhere, right? I cannot answere whether you are up to the task of replacing the stuff necessary to do the change over. If we are talking just a couple of change over valves that screw onto the existing R12 valves then I imagine you'd be up to it. How are you going to go about evacuating and recharging the system?

I have never done this one myself but here is a really cool backyard trick to evacuate your system. When I do it in the shop I simply hook it up to a vacuum pump and it sucks it down to right at 30Hg. I was talking with a shadetree mechanic and he fashioned himself a hose that connects the low side port of the a/c to the intake manifold and lets it idle!! That is so simple it is almost stupid. Sure you are not going to get more that 18-20 inches of mercury out of it but is that not better than nothing? Old dude said he'd been doing it that way for years and years and never had a problem with it. Understand that the reason you put it under a vacuum is to get the water to boil into steam so it can be sucked out in a gaseous state. At 30Hg water will boil, what does it do at 20Hg? I don't have the answer to that one but I still say that it is better than nothing and for a back yard a/c job it is pretty darn good.

Mark