Exploring Automotive Electrical Faults

Three Reasons Why A Professional Air Conditioning Retrofit Is A Better Idea Than Do-It-Yourself Options

As a result of the Montreal Protocol adopted in 1987, production of the R-12 refrigerant (which was used in auto air conditioning systems for much of the previous century) is now banned in the US. R-12 is consequently hard to come by, and many owners of vintage and antique cars are looking for another option. One such option is to have these air conditioning systems retrofitted for use with today's accepted refrigerant, R-134a. Here are three reasons why you should have your car's air conditioning system professionally retrofitted by a mechanic instead of trying to do it yourself.

1. Replacement without retrofitting isn't a workable option.

Filling an unaltered system with new refrigerant doesn't work because the system was specifically engineered for R-12. Problems the new refrigerant can create in the old system include:

  • The effective use of R-134a requires larger system components, such as a larger condenser and a more powerful fan. In the absence of these or similar amendments, the added strain on your system may be great enough to cause the compressor to break down.
  • R-134a's lubricating oil can react with R-12's oil, causing disastrous results. If any traces of R-12 remain when you introduce the newer coolant, this reaction may create a gooey, gelatinous substance that can clog the compressor and cause it to fail.
  • R-12 is made of larger, coarser particles than R-134a, so a system meant to hold R-12 won't necessarily work with the newer refrigerant. For example, vehicles produced before the early 1990s utilize hoses that will easily allow a great deal of R-134a to escape. 

2. Basic do-it-yourself retrofit kits can cause your system to work less efficiently. 

R-134 is a different chemical and consequently requires different conditions for optimal operation than R-12 does. Because of this, using it in a system that's still mostly designed for R-12 can result in less-than-ideal results. Many car owners install a do-it-yourself retrofitting kit and then, because their cooling system works less efficiently, develop the opinion that R-134a is an inferior coolant. This is not the case; it simply requires a different system of operation. One difference is that it needs more pressure than R-12 for best functioning. The recommended pressure for R-12 is 117 PSI (at 100 degrees), whereas 124 PSI is required for R-134a. This means that in an R-12 system with minimal retrofitting (such as the simple valve replacement supplied by retrofit kits) R-134a operates at a disadvantage. 

3. Different makes and models of cars require different retrofitting techniques.

An experienced mechanic knows the idiosyncrasies that can be expected from each type of car and can predict how best to adapt retrofitting techniques to your specific vehicle. This specialized knowledge greatly increases the chances of a successful retrofitting experience.

No matter what type of old car you have, a functional air conditioning system is crucial for your comfort and well-being. Find a professional mechanic you trust so that your air conditioning retrofit will provide the cooling you need this summer.

For more information, contact Aamco Transmissions & Auto Repair or a similar company.