A/C conversion question

I have an '88 Accord and the A/C system needs to be recharged so I was thinking about doing the R12 to R134 conversion. The compressor still turns on so I know it still has freon in it. My question is do I have to remove this old freon before I add the new R134 or can I just mix them?

If it has to be removed can I do it myself? And if not, how much does it cost for a mechanic to suck it out?

And my final question is, once all the R12 is removed is there anything else that needs to be replaced that isn't included in the conversion kit? (I thought I remember reading that the evaporator/dryer needs to be replaced when all freon is removed).

The two freons should not be mixed. The R12 should be evacuated by machine. Whenever the system is being worked on, it is a good idea to change the receiver drier. This collects moisture, metal particles, and other contaminants. If you don't, the new 134a will have garbage circulating in the system. You may want to change the orifice tube (if applicable) and convenient. You will also need conversion adapters which will convert the R12 fittings to R134a fittings where the charging manifold connects. I would also recommend a system flush which will remove R12 residue, compressor oil and contaminants in the lines and other components ( such as condenser, compressor, evaporator, etc.) before charging the system with R134a. If there is a lot of metal particles in the system, your compressor may be on its way out.

If your car was designed to operate with R12 I would stick with it. You could experience hose and seal incompatabilities, refrigerant breakdown -- if you don't get all the old oil out, reduced performance by about 10%, increased compressor head pressure - shorter compressor life, etc. Converting the system will be expensive and tedious, and yes, you would need a techinician to remove the existing R12. So I would suggest taking a quick online test for $10 and getting a 609 MVAC certification so you can purchase the R12 and do all the AC service and repair. Just go to EPAtest.com and you'll find out everything you need. I did it about a year ago and it has saved me a lot of money!

Good luck!

this thread is more than two years old.

don't bring back old threads. if it's more than 3 months old it's dead and should not be brought back unless neccessary.

Thank you 2.2.