Refrigerant R12 to R134A conversion?

You don't....... it takes changes that you cannot do.

You junk it and buy another fridge

Instead of your fridge , "Polar Bear" and "Propaganda" should be junked before to the trash truck.

Refrigerant R134A was designed to easily replace R12 -> almost identical parameters as pressures , temps , ...

The only serious problem is enviromental , because although 134A is ozone safe , R12 IS TERRIBLE.

So the serious problem is what to do with the R12 taken out before thinking in inserting the R134A.

Some ignorants just cut the high pressure pipe near the compresor and hear R12 fly. In US this can take a penalty of up to 25.000 usd , so don't even think in doing that.

Taking the problem from beginning think that when fridge is off pressure begins to be the same in all points of the pipes reaching about 70 psi in all circuit , so when you make a cut , R12 gas will fast scape.

To avoid this 2 main options:

1 Cut in the straight part of the capillary pipe: First with a hammer kick the pipe making flat in about 1 inch length and then cut in the half -> the 2 flat parts of the pipe will have no gas scape, so you can forget 1 and lime the second until you hear freon begins flowing out -> plug in the flexible hose of a comercial Ozone Saver

Recovery Bag and stop when volume stops increasing.

2 Buy a piercing valve for the diameter of the service pipe of your compressor (the one that rises up unconnected). This valve allows you cut the pipe without R12 escape if you follow instructions. Buy a manifold with 2 valve , 2 gauges and 3 hoses (red , blue and yellow) and a vacuum pump. Here the more than 100 usd will let you extract almost ALL R12 to a freon recovery tank and afterwards insert the R134A following all handbooks instructions, and even repair the refrigerator of an attractive blonde that lives near you.

R12 To R134a Conversion

R12 To R134a

I wouldn't bother doing it. It's just like converting vehicle's AC system over. The R-22 is evacuated, some detergent is pumped in then circulated by the compressor for a set time. Then it's drained and a few components are replaced to eliminate any trapped R-22. The R-134 is installed and all works swell for awhile then the compressor craters. Had it done to my '88 G30 work van by a professional vehicle AC shop who said up front it'd be a crapshoot. Could last a few months or a few years. Mine conked out after 6 months.

The price of R-12 has dropped considerably so there's no real need to switch over unless you plan to replace the compressor, Then you can get all the stuff and do it yourself. Do it before the old compressor conks out and you can turn it into a vacuum pump. I used one when converting the van to a R-134 system with all new parts except the for the coils. Worked like a champ.

Don't bother. The compressor oil used with R-12 is not compatible with R-134A and you have no way of getting the oil out of the compressor without cutting the lines and taking it out. At that point you might just as well buy another refrigerator, if it is working fine with R-12 there is no reason to do anything to it in the first place.

not worth it, I did one with 409a, (as experiment) but you are not supposed to the head pressure runs too high on a cap tube situation. Works fine with TXV. But just get some R12. Or buy a new box..

1989 SILVERADO PICKUP. AC BLOWN SEAL. I REMOVED THE OLD AC COMPRESSOR AND REPLACED IT WITH A REBUILT. I DIDN'T USE A VACUUM PUMP, I ADDED THREE CANS OF 134A THREE YEARS AGO ITS STILL 40DEG F AND WORKING FINE. I BOUGHT A SMALL GUAGE @ AUTO PARTS WHEN THE PRESSURE ON THE LOW SIDE WAS IN THE GREEN, I PUT THE CAPS BACK ON THAT,S IT.

BIG JIM.