1984 Chevy Monte Carlo convert r-12 system to 134A

ALEX SANCHEZ

MEMBER
1984 CHEVROLET MONTE CARLO
V8
2WD
AUTOMATIC
139,000 MILES

I recently accuried this car but the A/C is not working. The pressure switch will not let the compressor magnetic coil enguage due to low or no gas in the system. I was told that the expansion valve must be changed to accomodate the new 134A gas as the pressures are diffrent and R-12 and is very expensive. I can't find find the expansion valve. This car comes with a radial type compressor diffrent to the older model which is also round but almost a foot long. I noticed by the evaporator compartment their is a large nut that couples to another pipe with hose that goes to the front radiator which the pipe had black dirt on it giving a sign of oil leaking out from it; hopefully this is where the leak is. I spoke with a friend who does commercial/residentials a/c and told me I may need to install a new compressor that works with the new 134A gas. I am not a professional mechanic but with the right instructions and component I am sure I can task this job. Now if a new compressor is needed how can I get the proper brackets for it to fit this GM 305 V8 engine. Is there a simple solution to this problem and what do I really need to change out for this coming summer in Naples florida.

1 Reply

HMAC300

MECHANIC
48,601 POSTS

If you see the black dirt thing that is probably where it leaked out. Asold as it is you will be very clucky for it to break loose to change the o ring that is leaking. But if youdo then all you need do is buy one of the kits priced anywhere from $30-40 nd read the instructions and install the R-134a to the system. You will h ave to add oil to the system which comes with the kit and the best way is to dump the correct amount of oil in the open pipe that you take off. Then add the freon with the adapters that come with the kit. There is no need to change compressors or other parts unless they ae bad. The reason yo ucan't find an expansion valve is there isn't one. All it has is an orfice that sometimes will plug by the way.