How do I change from r12 to r134a refrigerant?

89 dakota v6 how do I do this and what parts will I have to replace if any.? what will I need ?

2 days ago
how much will it est. cost to have it done?

The most important thing is to flush all the old mineral oil out of the system.Any mechanical joints you open up,change the O rings and lubricate with the new synthetic oil you'll be putting in the system.If you attempt to use an old O ring.it will leak.Make sure you pull the compressor off to drain all the oil out,turning the compressor shaft to expel all oil.Buy the system flush to put in the condenser and evaporator and clean with compressed air.Change the reciever dryer and orffice tube or expansion valve, pull vacuum and test for leaks.Charge system.

you have to get a new a/c system

They sell conversion kits for these. I bought one for an 86 F150 I used to own. The big problem with the conversion is that the oil used in the two different types of refrigerant isn't matched. When they mix together it forms a really thick goo that will clog up your system. To do it right you have to have the whole system flushed out. You can also have to take off the compressor and drain the old oil out and replace it with r134a matched oil.

Need to replace all line seals, compressor oil, pressure test to see if the evaporator and lines will hole the pressure because 134 operates at appx. 60% higher pressures, replace resavoir because it holds a filter that must be replaced.

Cost, nearly the same as a new system, but you have to verify with a good A/C shop 1st.

Training 1st. Recover and recycle machine second. And 3rd, a conversion map so you know how much R134a to charge it with. Wow, that cost lots of money. differ easy to over charge the system.
Go pay the man to do it right. you'll like how it works when they're finished.