How to add R-12

Kevin,

The compressor on a vehicle is not semi hermetic, it is a swash plate or or conventional reciprocating type with crankshaft, connecting rod, piston and cylinder..

The 409-A blend can be used with Alkybenzene, Polyol Ester or in some cases Mineral Oil which is used with R-12. There becomes a concern with using mineral oil when the temp on the unit is below -20F, then there is a possibility of oil migration out of the compressor which can cause damage.

On vehicle compressors, the temp is usually between 36F-43F with a 70F temp entering the condenser.

Steve

Let's add this to the mix:
http://www.techmgmt.com/air/feature.htm
In theory this is a non flamable substitute for R-12 and has better performance AND is approved by the EPA. Make your own conclusions but I will have to check it out.

George Wroclawski
83 911SC Cab/Euro