123 exp valves are easy to get at, right under the r/h dash, just pull off the plastic trim and look up. I've seen a few oddball aftermarket systems that had parts in weird places but, most are right there.
4 o rings on the valve, 3 or 4 on the dryer, 2 or 3 on the condenser, most 123's use the York piston type compressor with the taperfit lines, no o rings, there are a few line joints under the hood that have o rings in them, replace them as well.
My wagon cooled well with the high side at 210 psi lo side at 33 psi, idle. The red switch throws the aux fan on around 225 psi which mine hit after 3 or 4 minites of idle. I ended up with 2 OZ of ester 100 in the dryer and thats all the oil that went in, if you's like, remove and drain the compresser, measure the oil that came out and replace with ester, same deal with the condenser. (most condensers hold 2 OZ except the monster in the 140 that holds almost 3)
I ended up with about 22 OZ of 134 in the 85. There again this is dependant on abient temps, air flow, evap size, condensor size and line lenght. Make sure the AUX fans work and your fan clutch is in decent shape. There again, I'd seal the condenser the the radiator as best as can be done without blocking the airflow over the radiator. (those little rubber seals on the 201 are great for this)
I've heard the storys about hoses that wick 134 through the walls and have never seen one leak that way with 134 unless it did it with 12 as well. Dont flip if you see 300 psi Hi side pressures as long as it dosen't get past that very far, if you freewheel the motor to 4 grand and it stays under 325, it'll be fine as long as your hoses are ok.
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.