Jump to content
Ultimate Subaru Message Board

Help with refitting 1992 Leagcy a/c from R12 to R134a


Recommended Posts

Hello,

 

I have a small big problem: I'm currently upgrading a 1992 Legacy a/c to R134a and to that quick connections of R134a systems. That's not the real problem since you get plenty of refitting adapters to convert that old R2 connectors. However, I have the problem that I can only get the proper adapter for the low-pressure side. That's 3/8". But the high-pressure side is smaller, should be 1/4". But I can just find adapters for 3/8" or bigger (both pressure sides have the same size on those offers) and sadly I can't get any informations here in Germany about the right adapters and it's also impossible to find a garage with the right adapters since all I know of have those new compact devices for filling R134a and newer.

 

I have found a few threads and informations, but nothing about the size of the high-pressure adapter nor where to buy it. I have also searched on ebay.com but also with no success, but perhaps I just search for the wrong thing. Any help is very much appreciated!

 

Thanks!

Link to comment
Share on other sites

Sounds like you are into doing things yourself, since you have already worked at sourcing retrofit adapters. If it were me, I would simply use the low port adapter only. I would add 2 cans of 12 oz size to an empty system of 134a refrigerant, using one of those cheap hoses with a gauge on the end. Don't bother to find the high port adapter.  I assume since the adapters are available, then the small 12 oz. cans of 134a are available to buy.  I have done the above conversions a number of times with good results.

 

The existing lubrication oil in the system for R-12 is not the best for R-134a. It is better to replace with PAG or Ester oil that is made for 134a refrigerant.

 

You don't say if the system leaks refrigerant or not. If so, you may need to replace some of the O rings that may be leaking.

 

I have some other thoughts too, but prolly better to contact me direct..........fish6525@gmail.com............(Rooster2)

  • Like 1
Link to comment
Share on other sites

Hmm that's a bit tricky to do it myself: Here in Germany it's extremely uncommon and unpopular to do such things yourself. You're almost seen as dangerous criminal if you let that gas loose... Too many greens here in this country :( So, you can't really buy R134a and PAG100 - or better said, it's much cheaper to let it be done in a garage than to buy that things yourself.

 

Last time, the guy at the garage refilled the system only with the low pressure side and it took hours to fill the system. Now I've changed the compressor because it went bad and now the system has to be refilled and I want to make it right this time. Ff course, if there's no solution it has to be done in the same way the second time, but I have the feeling that there wasn't enough R134a in the system last time as well...

 

Problem is also that there aren't many cars with R12 a/c here in Germany: There weren't many back in the 90ies in general since it's not that hot here (or better it wasn't that hot...) and many of those with a/c are gone thanks to rust and the stupid German tax policy for old cars. :( So it's hard to find anyone who really knows about that old a/c. And Subaru Germany is expensive as hell :(

Link to comment
Share on other sites

Rooster2 is correct that you can just fill from the low side of the system but if thats what you did before and it took hours as you say... I would expect some type of blockage either in the orifice tube/H-Block... not sure what kind was/is used but they are both expansion valves.. but either way both of those devices are inline with the system to atomize the refrigerant and allow absorption of heat but can get blocked with debris... especially in an event like compressor failure.

On most of the A/C systems I have done... not retrofitting but repairing It is required (to have a warranty)  to replace all of the components except evaporator (under the dash) especially the expansion valves... due to blockage and flushing the entire system with A/C flush solvent...

Not sure what all had to be changed over in your situation but if those components are original I would start with replacing or if unable to replace try and clean as best as you can.

Also if filling from low side takes awhile try starting the car and turning on the A/C this will allow the compressor to help the flow of refrigerant through the system

If its working properly the compressor should start to cycle on and off until the system is fully charged and then stay on continuously when A/C is on.

Hope this helps

Greg

Link to comment
Share on other sites

Hmm, I have a donor car, where I pulled the compressor, so I will pullthe the other components as well and replace them. Seems to be better.

 

The idea with turning on the a/c while filling the system is great! I guess that should work and that will be the way to go or at least to try.

 

I have another joker: A buddy who works in a machinery construction company will try to make a proper adapter, perhaps this will be successful. Anyway, I will report :)

 

Thanks!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...