One of my projects is a 90 Legacy that is destined to be my wife's (once I get it running). Amongst other issues, it has a seized A/C compressor and most of its refrigerant is gone.

 

I have a replacement compressor, but am trying to decide what to use to replace the refrigerant. My options seem to be:

A) have a service center replace the R12

do a conversion to R134a, either partial (refill only) or full replace lines and maybe some components

C) use an R12 substitute such as Freeze12 (which a relative says works great)

 

Any recommendations or thoughts?

I switched over to R134a last year without changing any of the hoses, seals, etc. Just removed the R12 and pulled a vacuum on the system for 24 hours and then bled in the R134a (luckily, we have the equipment and certification to do refrigeration work). The R134a doesn't blow quite as cold as the R12 did, but seems to keep me comfortable during this current hot spell. Only difference I notice is that it doesn't blow as cold while sitting at a traffic light, but once I get going down the road, it's fine again. If you didn't have any issues with the compressor, I'd just have some R12 added where you can. A switch to R134a will get you to what is now "standard". I don't know anything about any of the other "special" refrigerants that are considered alternatives to R12. I made the switch last year on my '91 Legacy wagon and everything still seems to work quite well. I have noticed an issue with the compressor starting to seize up when I run it for a long time, but it was doing that with the R12 also and I guess I'll have to replace the compressor sometime. Hopefully it will take me through this summer and fall.

I've replaced the R-12 with Freeze 12 on my 91 and 92 Soobs. Cooling is fantastic.

 

Since you'll have to crack the system open, I'd probably go for the switch to 134a. As you do research on this, note that most recommend the system be flushed to remove the old oil in preparation to keep the 134a compatible oil from the old oil. While I haven't run across anyone that has had the oils gel, it sounds like a real possibility. You might also check:

 

http://www.aircondition.com/

 

for more info.

 

Nick

Also Google: Duracool

 

Friends have used this in their old R12 systems with really good results.

Regarding oil compatability, I know enough not to use PAG oil without a major cleanout effort, and haven't heard of any major problems with the oils used in conversion kits.

 

Ed, have you had any evidence of refrigerant loss through the hoses (as was originally a concern with conversions)?

I had to add a small amount this spring, but I suspect I was low to start with on my initial re-fill. I'll let you know how it survives this summer.

Regarding oil compatability, I know enough not to use PAG oil without a major cleanout effort, and haven't heard of any major problems with the oils used in conversion kits.

 

Ed, have you had any evidence of refrigerant loss through the hoses (as was originally a concern with conversions)?

My personal preference would be Freeze 12 or Freezone rather than

Duracool. Duracool is not approved for use in auto ac systems . It works

just fine, it is flamable though. However most any AC chemical when

it contains lubricating oils will burn, and R-12 was very toxic when

burned. Still Duracool is not approved mainly for its flamability.

Freeze 12 and Freezone are not flamable (except for the fact they

contain flamable oils). 134A also has advantages....you can get it

almost anywhere, it does require flushing the R12 systems before

installing, something the others don't.

It is illegal to mix any refrigerant with R12, even though Freeze 12

and Freezone will mix with R12 and work just fine . If you are going

to do it right....have the system flushed before you install any

refrigerant.

My experience with 134 in my 90 Legacy has been very good.

It cools as well any AC I have seen in a car. The one thing

to remember is to start slightly undercharged and monitor the

cold air temperature. Add SMALL amounts of 134 till the temperature

quits lowering and then rises. Remove the last SMALL amount added

and quit there. My car likes 32 pounds low side pressure and provides

35 degree air on the opern road and 40 degree in town.

It does as good as any of my cars with R12.

And yes, I am licensed.

 

Richard1296

Your also going to need a new receiver/dryer, since the system has been open and the compressor is seized. Fear is usually that there are bits of compressor in the ac system and it should be flushed out.

 

nipper