I've a 1993 2.3 and 1992 4.0 both with a/c systems down. On the 1993 Ranger I tried to loosen the evaporator tube nut to install the new acuumulator now it looks like there's going to have to be a new evaporator. Without hardly any pressure that tube just twisted like it was nothing. Someone told me I have to spray it with wd-40 3 days prior to loosening it. I doubt that would even help. Hopefully removing the evaporator case cover under the hood won't be too time consuming because now I've got to. So I don't want to make the same mistake on my 1992 4.0. I need to change the accumulator, orifice tube, flush the evaporator, condenser, install the new hoses, and compressor before evacuating and recharing. Is there anything that makes it a breeze to loosening those evaporator and liquid line nuts without destroying the evaporator?

 

evacuate the refrigerant
Use two proper sized flare nut wrenches.

 

There should be a hex nut on the evaporator line. You're supposed to use two wrenches when disconnecting the accumulator: one to loosen the nut on the accumulator, and one to hold the evaporator line and prevent it from twisting.

 

Get some Nylog if you have any snap-together connectors. They'll wiggle & leak. Pick the oil you want to use if you are converting to R-134a. PAG or Ester(POE). PAG is very hydroscopic and will pick up moisture from the air quickly... Ester more forgiving.
Most systems take ~10 oz of lube. Pre-distribute it into the condenser, evaporator and accumulator, leaving ~50% +/- for the compressor itself. Pour the oil into the compressor and rotate it several turns to distribute the oil internally, and lube the internal moving parts. When you go to assemble, lube all O-rings with oil or Nylog before assembly to ease sliding together and provide a quick seal. Nylog is the lube you can never get off your hands and will stay on O-rings, etc, and keep them protected from rubbing friction, and hopefully leakage. I think there are two flavors, depending on refrigerant or oil selected(memory? used to have one..), red or blue.
Do not open any components to the air until the last minute. Remove the caps on the evap and accumulator right before you put them together. Do the evacuation immdiately after assembly to remove any humid air from the system. That leaves the desiccant as intact as you can make it, so its water-grabbing powers are at max.
tom