Need Trustworthy A/C guy.

[Tools R Us]

The o-rings are commonly available in metric kit form, the small kit is less than $10. The original o-rings are only good to about 200F and some newer A/C chemicals will attack them, the newer green ones are good to 300+F and much more resistant to chemicals.

http://www.ackits.com/merchant.mvc?...e=CP3008&Category_Code=Toyota92LandCruiser4-0

The flush procedure is simple, I use lacquer thinner, pour or squirt it in then blow it out with plenty of compressed air, repeated until clean, then blow plenty of air through to remove the solvent. The condenser and evaporator need to be done, but if your replacing the o-rings the ports are open anyway.

http://www.autoacforum.com/messageview.cfm?catid=20&threadid=9172&FTVAR_MSGDBTABLE=

 

[1972FJ55]

First off, I agree with not retrofitting. Our experience is that it does tend to leak out faster and not cool as well as R12. In northern latitudes it may not be an issue, but in Phoenix you can't afford to have a system work at less than 100%. My advise is to find and fix whatever the leak issues are, and continue with R12. Some areas to visually check-you're looking for oily residue:
1) On the compressor, there is a plate held on with 4 socket head screws, where the hoses attach, the hex shaped gasket underneath tends to flatten out and leak.
2) Look at both connections at the condenser.
3) Look at the discharge hose (the one from the compressor to the condenser)
4) Look at the compressor body where the seams are ( sometimes can be confused by #1 above)
If you find that it's in the connection(s), buy a seal kit such as Santec #MT2581, which will contain all the seals/gaskets in the system, should be about $6.
Let me know if you need more info.
Rex