Re: A/c fixes

[jtrealty@xxxx]

You should not let anyone talk you into converting from R-12. The EPA 
has not approved ANY drop-in replacement for R-12. The seals and "O" 
rings are not compatible with the lubricant used for other gases. The 
oil in your system cannot be entirely removed without completly 
flushing the system and rebuilding the compressor. Some of the 
advertised replacements are really blends of several gases including 
propane and butane. All replacements run at higher head pressures and 
require a larger condenser to achieve the same capacity as R-12. Even 
if you switch no one will be able to tell you how long the system will 
run before the oils destroy metal parts and seals. Even though R-12 is 
going for about $60 a pound you only need 2.5# so it is not the worst 
thing to stay with. The labor will cost more than that no matter what 
you put in. Make sure that the system is THOURGHLY leak checked so it 
isn't wasted. Most good shops use an inert dry gas (like argon or 
nitrogen, or even instrument air) to test the system and sweep out any 
contaminates in preparation for the Freon. A good shop will also want 
to replace the dryer if the system has been open to the atmosphere. If 
you do change to a substitute make sure that the service valves are 
changed and the system is properly labled so no one will mistakenly 
put R-12 in again.
David Teitelbaum
vin 10757



[moderator snip]