A/C conversion to R134a
Thread Starter
Intermediate
Joined: Jun 2005
Posts: 48
Likes: 0
From: Queen Creek AZ
A/C conversion to R134a
Hey girls and guys I need help and I am hoping someone out there has done what I need to do, my A/C doesn't work and this is because the previous owner removed the R12 Freon, rather than spend a fortune on R12 I am going to convert to R134a .
my questions are...………………
1/ How much R134a do I need
2/ Are there certain components that I must replace
3/ Are them components that would be good to replace but not essential
I have all the equipment to do this conversion but have never done it on a C4 Corvette.
Thank you in advance for your input.
Gary
Burning Brakes
Joined: Jan 2019
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From: Park City, TN
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Curious, why did you start a second thread on this?
https://www.corvetteforum.com/forums...-question.html
https://www.corvetteforum.com/forums...-question.html
Melting Slicks
Joined: Jun 2014
Posts: 2,236
Likes: 498
From: NJ
Just get the R-12 refrigerant it's easier. But if not you need to flush the old oil from the system and replace with PAG oil and refrig. charge weight is 80% of original capacity. Note the conversion is not nearly as efficient as R-12, the r-12 condenser is too small to handle sitting in traffic on the highway it's ok. I've done this before and if I had to do it again I would get the R-12. Just saying...
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 764
Just get the R-12 refrigerant it's easier. But if not you need to flush the old oil from the system and replace with PAG oil and refrig. charge weight is 80% of original capacity. Note the conversion is not nearly as efficient as R-12, the r-12 condenser is too small to handle sitting in traffic on the highway it's ok. I've done this before and if I had to do it again I would get the R-12. Just saying...
R134a is NOT less efficient than R12 – Actually R134a is more efficient.
Pound for pound R134a is a more efficient refrigerant than R12, however it runs at higher pressures in some aspects and therefore requires more effective condensing. Whether R134a performs as well as R12 in any given a/c system depends upon system components and the amount of R134a used.
Given two identical vehicles, each with the same weighted amount of refrigerant, the vehicle with the R134a has the “capability” to remove more heat (measured in btu’s) from the vehicle than the same type of vehicle using the same amount of R12.
The most common influences which effect the capability of R134a to perform well are the condenser, in some cases the superheat setting of the expansion valve or the amount of R134a. Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the car’s interior. And by “matching” the correct amount of R134a to use in a given vehicle, correcting the superheat of the expansion valve (if necessary), you can in some manner nearly balance or match the amount of heat drawn out by the evaporator and released by the condenser.
These efforts to “balance” the system can not be realized if there are problems within the a/c system, such as: poor performing compressor, dirty condenser or poor air flow through the condenser, malfunctioning expansion valve, water or air in the system, improperly operating fresh air or heat input in the climate-air mixing system.
Pound for pound R134a is a more efficient refrigerant than R12, however it runs at higher pressures in some aspects and therefore requires more effective condensing. Whether R134a performs as well as R12 in any given a/c system depends upon system components and the amount of R134a used.
Given two identical vehicles, each with the same weighted amount of refrigerant, the vehicle with the R134a has the “capability” to remove more heat (measured in btu’s) from the vehicle than the same type of vehicle using the same amount of R12.
The most common influences which effect the capability of R134a to perform well are the condenser, in some cases the superheat setting of the expansion valve or the amount of R134a. Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the car’s interior. And by “matching” the correct amount of R134a to use in a given vehicle, correcting the superheat of the expansion valve (if necessary), you can in some manner nearly balance or match the amount of heat drawn out by the evaporator and released by the condenser.
These efforts to “balance” the system can not be realized if there are problems within the a/c system, such as: poor performing compressor, dirty condenser or poor air flow through the condenser, malfunctioning expansion valve, water or air in the system, improperly operating fresh air or heat input in the climate-air mixing system.
