Converting A/C to 134

What is needed to convert an older A/C system to 134? I want the system to look original, so can I use a RV2 type compressor?

Use R-12 and it will look and perform as original.

Just put the 134a fittings on it, charge it, take fitting back off.

Does the RV2 compressor have its own oil sump? If not, note that R-134a is not miscible in the mineral oil used in R-12 systems... and modern compressors depend on the refrigerant to carry the oil and keep the compressor lubricated.

Compared to R-12 the low side temp/pressure curve is not identical, although it will work OK. An expansion valve calibrated for 134a is preferable.

I'd really recommend a better condenser, or at least a pusher fan in front of it, or you may be unhappy with the performance at idle. Central TX is a pretty hot place in the summer.

If you're not concerned with anyone else ever servicing your system, or the legality, and it's leak-tight, you could consider Envirosafe ES-12 (propane/butane mix). Cheap and effective.

If you do not know the answer to that do not give advice on converting an RV2 system to R134.

If you do not know that it's important (whether oil needs to be carried by the refrigerant or not) then you can stuff your usual attempt at smart-ass rejoinders. I've probably been converting and working on a/c longer than you've existed.

Why don't YOU try giving some advice for once, instead of attacking individual posters? Another idiot for the Ignore list. <plonk>

I gave sound advice, you obviously do not know crap about the RV2 system when it is functioning as designed. Why would you know more about successfully converting it to a type of Freon it was never designed to use?

You do not.

Run R12A in it and it's a drop in replacement.

No need to mdify desicant dryer or readjust expansion valve anymore like on this article says, they are available at RockAuto from FourSeasons ready to R134

These threads always end up being rife with misinformation and anecdotal hillbilly conversions.

Yes, some folks merely charge the system with R-134A with no other changes but this a simple case of doing it wrong and getting away with it.

There is no such thing as a "drop-in" replacement for R-12, a true drop-in would be a single component refrigerant and all of the so-called drop-ins are blends of other refrigerants or hydro carbon (explosive) mixtures.

The problem with blends is the size of the molecules, the different components in the blend have different sized molecules so, when the charge leaks off (all automotive systems leak), this makes the blend lopsided so you can't simply top off the system.

Again, R-12 systems deserve R-12.

As a casual reader observer, I thought R12 was illegal? I have 2 systems in my Magnums with r12. One day I'll need to top off. Can it be had?

R12 isn't illegal. It is getting harder to get though the price has come down from the crazy days. You need a license to get it.

https://www.macsw.org/WEB/MACS/Section_6...dd-27fd9b9153f6

As for someone's definition of drop in, whatever. R12a requires no parts changes, no oil changes to run, though a new receiver drier is always a good idea. The EPA requirements and definition makes it clear that nothing is considered, by the EPA, to be a drop in substitute.

I'll bet you can find R12 for about $20 a can. Maybe even from other Moparts members. It is legal to send the cans by mail. It has to be declared and sent by ground, but no big deal.

A ballistic shield should be on the parts list.

Dr. Charles asks;
"Does the RV2 compressor have its own oil sump?"

Yes, the RV-2 compressor has its own oil sump.

And its own oil pump too.