134a conversion question

[TAZZ]

I’ve got a 72 charger that needs the AC put back in service after new engine install. We were told when we bought the car it had been converted to 134a. When asking around for a shop to get it up and going I was told it would need a large condenser to work with the 134. Is there a certain ”size” or other way to tell if the condenser has been upgraded? Thanks

 

[YY1]

My 73 OEM condenser is working fine with 134a

 

[68BabyBlue]

OEM condenser in my '69 GTX works great with 134a.

 

[gtx6970]

I had a 67 Coronet all stock ac system. converted to 134a

No issues and kept the car nice and cool inside

 

[PurpleBeeper]

The easy way to tell is to look for the “low side” fitting where you put in freon. If the fitting fits the 134a filler hose, it has been converted. If the 134a hose does not fit the fitting, it’s still R-12

 

[rickseeman]

They were wrong. I've heard that smack for 30 years. When 134A came out they said it had less cooling power. Well maybe in a laboratory, but not in real life. After converting my 70 Cuda (and other cars) it would blow 39 degrees. It couldn't have been better than that new.

 

[451Mopar]

If already converted it should be fine. When converting, need to clean all the old oil out of the system.

 

[Tony Tee]

It will work ok. But it will work better with a larger condenser for sure.

 

[68BabyBlue]

They were wrong. I've heard that smack for 30 years. When 134A came out they said it had less cooling power. Well maybe in a laboratory, but not in real life. After converting my 70 Cuda (and other cars) it would blow 39 degrees. It couldn't have been better than that new.

I've owned two factory A/C '69 GTXs. Ran the first with R12 in the 90s. Current one runs 134a, no detectable difference, blows 39 degrees.

 

[YY1]

Be sure to use "green" O rings when putting it back together.

 

[Some Car Guy]

Take all fittings apart and check for the green o rings. My 69 GTX was converted by a shop. They left half as the old black ones and those melted away from the 134. Also they installed new hoses and one they saw fit to leave the o ring out completely.

Since I did the going through with a new dryer and expansion valve, it cools good. Factory condenser. Be sure to change or plug the schrader valve as it can leak too. That was my mistake the first go round.

 

[qkcuda]

Does 134 require a new or different expansion valve? I do have a replacement expansion valve that I bought for my previous car but never used. I will be swapping engines this winter, and will need to remove the compressor and convert the system.

 

[Some Car Guy]

I do t think you can run a different expansion valve than what the factory had. At least not with an oe system anyway. I replaced mine as I saw a lot of info saying you should run a new one if you are doing much work in the system.

It's been over a year, I can’t remember the exact details. I thought mine looked really old and the compressor looks kinda new or rebuilt so I think that was why I changed it. Four seasons brand from rockauto or Amazon. Get the drier too.

Detroit muscle technologies is I think the name of the place that has a nice green o ring kit with the oil. He posts on moparts.

 

[RJRENTON]

Does 134 require a new or different expansion valve? I do have a replacement expansion valve that I bought for my previous car but never used. I will be swapping engines this winter, and will need to remove the compressor and convert the system.

The SUPERHEAT (ability of the refrigerant to absorb more heat, than the initial latent heat to cause the refrigerant to boil in the first place) CHARACTERISTICS is determined by the Thermostatic Expansion Valve's (TXV) orifice, internal spring pressure and internal gas pressure. It’s USUALLY the same gas type as the refrigerant being used, R134A in this case. R134A has a different specific heat characteristic than R12....the system will operate more effectively when using the correct TXV for the refrigerant being controlled....will it work ok??....yes but just not as well......the larger the CONDENSER, the lower the compressor's discharge pressure will result and the ability to have a larger liquid refrigerant storage capacity.......just my opinion, of course......
BOB RENTON

 

[WileE]

I've done a number of conversions over the years. From simple fitting change, to complete system overhaul. All worked fine. You don't need a different condensor.

 

[RJRENTON]

I've done a number of conversions over the years. From simple fitting change, to complete system overhaul. All worked fine. You don't need a different condensor.

TRUE....you don't NEED a new condenser.....but if one is available, leak free, and matches the fittings and layout, as I noted, a larger condenser will lower discharge pressure as the refrigerant will be condensed at a lower temperature, due to more surface area and subsequently lower pressure. The condenser will hold approximately 1/3 to 1/4 of the total refrigerant oil in the system and should be flushed, if using the original condenser, b4 switching to R134A as the oil is different. Also, change the receiver/dryer as the dessicant will be saturated with oil and moisture. R134A has different operating parameters and hence, different cooling capabilities, compared to R12.....just thought you might like to know....
BOB RENTON .

 

[WileE]

TRUE....you don't NEED a new condenser.....but if one is available, leak free, and matches the fittings and layout, as I noted, a larger condenser will lower discharge pressure as the refrigerant will be condensed at a lower temperature, due to more surface area and subsequently lower pressure. The condenser will hold approximately 1/3 to 1/4 of the total refrigerant oil in the system and should be flushed, if using the original condenser, b4 switching to R134A as the oil is different. Also, change the receiver/dryer as the dessicant will be saturated with oil and moisture. R134A has different operating parameters and hence, different cooling capabilities, compared to R12.....just thought you might like to know....
BOB RENTON .

I know very well, I've done quite a few AC recharges/services, as well as various conversions in 55 years. And yes, the receiver-drier MUST be changed to a new one.