r134a or freon

[74Dusterkid]

i will be picking up a motor with the a/c compressor,condensor,the plumbing and all what would be the cost to put freon back in?or would it be alot cheaper to convert the system over to r 134a? i dont know if i want the a/c in the car until i see how much it will cost to put it back on. thanks craig

 

[dla4567]

the refrigerant isn't that expensive ($30 -$40).but if the system has been open for awhile it should have a new drier and oil change. the most important thing is that it is clean and leak free. then it will need to be vaccuumed to remove all moisture and leak tested, then recharged. There are several replacement refrigerants available to replace the original R-12.R 134 is an HFC refrigerant and requires that 95% of the oil be changed to POE oil.This can be difficult to do and may take several oil chnges to get done(expensive).I've had good luck with 409A as a replacement and it will work fine with the oil already in the system (mineral oil).If you do not have the tools or experience to do a/c then it could cost you a few hundred dollars to have repaired. Shop around and get someone good to do the work, otherwise it may not work for long. good luck

 

[74Dusterkid]

yea i just wanted to get opinions on the matter. i probably will take it off but i will keep the whole set up so that if i ever want it again i just have to put it back in and charge it.

 

[shhnappa]

the refrigerant isn't that expensive ($30 -$40).but if the system has been open for awhile it should have a new drier and oil change. the most important thing is that it is clean and leak free. then it will need to be vaccuumed to remove all moisture and leak tested, then recharged. There are several replacement refrigerants available to replace the original R-12.R 134 is an HFC refrigerant and requires that 95% of the oil be changed to POE oil.This can be difficult to do and may take several oil chnges to get done(expensive).I've had good luck with 409A as a replacement and it will work fine with the oil already in the system (mineral oil).If you do not have the tools or experience to do a/c then it could cost you a few hundred dollars to have repaired. Shop around and get someone good to do the work, otherwise it may not work for long. good luck

I was told that if you convert from R12 to 134A, you need to remove the EPR valve and Orifice tube, any truth to that? Otherwise, the rubber lines need to be changed, but everything else will work. Any thoughts?

 

[dla4567]

It would be best to replace the epr valve and orifice tube to match the new refrigerant, but most replacements are close enough not to make a noticable differance. when using a blend refrigerant that contains r-22 then nylon barrier hoses are recommended to prevent leaks.

 

[shhnappa]

It would be best to replace the epr valve and orifice tube to match the new refrigerant, but most replacements are close enough not to make a noticable differance. when using a blend refrigerant that contains r-22 then nylon barrier hoses are recommended to prevent leaks.

Thanks for the reply. Here's where I'm at (sorry to steal the thread but I think this will help out all). I sent my hoses to Classic Auto Air in Tampa, Fl to have them restored, and they are putting the barrier hoses on there ($126.00 ea.), he told me other than the normal replacement parts that should be replaced Expansion Valve, Receiver/Dryer, Condenser (mine was shot) and Compressor (also shot), he said that I have to remove the orifice tube, EPR valve, and install a thermostat ($45.00, from them) to keep the evaporator from freezing, which will cycle the clutch, and that is all I should need. He also said to run 80% of the recommended full R12 charge if I'm going with 134A, full 134A charge will be too much. I also told him that my '68 Cuda did not come with a low pressure cut-off switch ($5.00 e-bag), and that I decided to mount one on the receiver/dryer to protect the Compressor in the event of a leak, he said that was a good idea. They just got my hoses and said it will take 3 - 4 weeks, he can't believe how busy they are with hose restoration at this time of the year, and in this economy, but it is what it is. Anyway, I'll post my progress and hopefully my victory!!!

 

[goldduster360]

Thanks for the reply. Here's where I'm at (sorry to steal the thread but I think this will help out all). I sent my hoses to Classic Auto Air in Tampa, Fl to have them restored, and they are putting the barrier hoses on there ($126.00 ea.), he told me other than the normal replacement parts that should be replaced Expansion Valve, Receiver/Dryer, Condenser (mine was shot) and Compressor (also shot), he said that I have to remove the orifice tube, EPR valve, and install a thermostat ($45.00, from them) to keep the evaporator from freezing, which will cycle the clutch, and that is all I should need. He also said to run 80% of the recommended full R12 charge if I'm going with 134A, full 134A charge will be too much. I also told him that my '68 Cuda did not come with a low pressure cut-off switch ($5.00 e-bag), and that I decided to mount one on the receiver/dryer to protect the Compressor in the event of a leak, he said that was a good idea. They just got my hoses and said it will take 3 - 4 weeks, he can't believe how busy they are with hose restoration at this time of the year, and in this economy, but it is what it is. Anyway, I'll post my progress and hopefully my victory!!!

What year is your vehicle? My 73 Duster has a factor installed thermostat, it is mounted on the passenger side of the evaparator case. Mine is adjustable too, which was required after I got a replacement copper evap form that same company in Tampa. The new one worked too efficiently for the old setting. I am still running 12 in mine but I have heard the expansion valve style like my 73 has is pretty forgiving with different refrigerants but you may have to vary the charge from factory specs as they suggested.

Let me know how your hoses turn out, I have a v/8 one that needs to get rebuilt before putting on my car.

Good luck with it.

 

[dla4567]

It is best to replace txv to match refrigerant, but r-12 and 134 are pretty close as it will probably work ok (some are adjustable). I prefer the epr valve over the t-stat as it derates a/c instead of cycling compressor, but either will do. If you put a low pressure switch on the reciever than it is more of a loss of charge switch than a low pressure switch, I prefer to install a low pressure switch on suction line, especialy if using a t-stat instead of an epr valve.R-12 condensers are to small for 134 and will cause a high head pressure, this will not cause a problem but if you are replacing it anyway, maybe they offer a larger one. 134 charge is approx. 80% of r-12 charge, but is best checked to get best operation, especialy if changing componants.


Good luck and keep cool!

 

[Stacked360]

R-134A lines have a nylon barrier layer where as R-12 lines do not. R-134A molecules are smaller than R-12 because of the lack of the Chlorine atoms. Even if you convert over to R134A you will still need an orifice tube or the better choice would be the expansion valve. If you use an orifice you must have an accumulator instead of a receiver dryer.