R134A Conversion

[Apowell@ezlink.com]

Friends, I've BTDT converting a Chevy pickup from  R-12 to R-134A. 
 Comments about the procedure:

To do it correctly, you MUST change both the compressor and the 
drier.  The compressor seals for 134A are different.  The difference 
will not be immediately apparent, but the 134A leaks more easily 
and you won't keep a charge with R12 seals.  The drier cannot be 
re-used with one refrigerant once it has been used with the other.

The lubricants used with R-12 and 134A are totally incompatible.  
In order to do the changeover, you need to have a shop use a 
vacuum unit and draw vacuum thru the system to clean it out.  
Failure to do this can result in compressor failure.

The R-134A will indeed work in a retrofit system, but will have 
perhaps 30% les cooling ability.  This is not apparent on the road 
but becomes apparent in traffic or other conditions when the engine 
is idling for a few minutes.  With the cooling capacity of Audi's 
systems, most of us would find the 30% capacity loss acceptable.

Having done this in Central TX, I don't think I would do it again in 
that particular piece of h*ll.  But here in Colorado or other most 
other more temperate areas, should work OK.
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Al Powell
Apowell@EZlink.com
1958 Fiat 1200 Spyder "Transformabile"
1983 Datsun 280ZXT
1990 Audi 200
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