Re: [Chevelle-List] a/c conversions

[Mistbluemalibu]

Jason,
I don't know much about automotive a/c, but I have worked on commercial refrigeration units that were originally R-12 units and used a drop in replacement to recharge such as R-409a and ICOR hot shot without retrofitting ANYTHING.  I just replace the filter dryer with an identical one, and pull a very deep vacum before charging.  I don't know why we can't do this on cars other than the fact that people in the automotive buisness want to make money by selling retrofit kits.  I guess the R-409a head pressure is a little high for hoses, but there are other R-12 drop in replacements now.  The just come in a 24 pound bottle.

Can anyone tell me why we can't use a drop in replacement in cars?

Pat