How much to convert "old" ac system to the new stuff???

I have a 89 suburban chevy and it uses the "old stuff", r 12 I think thats what its called. A shop here says I should convert it to the " new stuff" 134 stuff. How much should it cost???? They qouted me at 1100 dollars.....

Here is a web page to explain the general procedure.
http://members.tripod.com/~jbabs714/autoac.htm#134
There are several opinions as to what has to be changed.. since R12 and R134 systems require different compressor oil. Some say that the entire system has to be flushed completely which requires a lot of work and perhaps a change of dryers (dessicant). Others say that you dont have to do all this stuff now....however, uncle sugar has specific rules that should be followed. The R12 is not supposed to be blown off to the atmosphere anymore....it has to be "recovered". A lot of shops will gladly "recover" it for you (remove it) since the stuff is worth $50 a pound or so. Also, there are specifics regarding the port change (charging ports) and the labeling of the system (must have a retrofit label). Do some research... the $1100 might include a new dryer, new compressor, etc while a cheapie job is just changing the gas and the ports.

Why do you want to change? R12 is a better referigerant and provides better cooling....only slightly better. It is quite a bit more expensive...your system probably holds somewhere in the 3-4 lb range unless you have rear air (adds a small bit)

mike in tucson

I paid $55.00 to have my '93 Blazer to use r134, and I went to Fleet Farm and bought a kit to change my '87 Mustang to r134, it cost me $26.00 and a auto shop vacuumed the old out for free, has been in the Blazer for 5yrs and the Mustang for 3yrs, without a problem. There is a BIG differance in price from r12 and r134, about 8-10x the cost, and need a lic to buy r12, not r134
I do not notice any differance in temp.

Pat

Just put Duracool in it, no changeover, works fine.

Good suggestion Pope. Duracool is not available in a lot of markets. Max-Cool is the same stuff and might be more prevalant in other markets, Fridge-cool comes to mind also. I like this line of thinking because if the person doing the conversion is not experienced, It is a pndora's box of nightmares not for the faint of heart. Mineral oil will coagulate upon contact of the PAG or Esther oils therefore the complete flush must be complete or this is going to be a repeated process with servicable parts being replaced a few times and flushing repeats, etc. Don't forget to replace all o-rings with the "green" 134 rings. 134 has a more gaseous expandible rate and is harder to compress to the state of R-12. This leads to some systems not being as efficient in the cooling department at the evaporator.