Air Conditioning Questions

[ITdude87]

Hey all.

So, I've known the AC in my 86' needed to be re-charged for some time now. The weather is finally starting to get nice and warm, and this would be nice to have.

My questions:

It looks like the old style "R12" connector is still present (screw type, not quick release), despite having some paperwork that the previous owner performed an "R134a Conversion".

If you were me - Would you safely assume it's OK to bring it into a shop to have the AC professionally charged up? Are there any "gotcha's" to look out for or mention? Is it even possible to re-charge these old gals with the R12 type still, or am I going to need to look at some kind of big kit to replace components?

I'm not a huge fan of the DIY AC kits you can buy at the parts store, but if push comes to shove and a shop won't touch it - Would this do the trick in a pinch, granted I buy some adapters from Amazon?

Cheers in advance!

[Chuck W]

When I resurrected my LTS, I got the AC working again. I replaced everything except the evaporator and the compressor. All the rest was new, including the hoses. I converted the system to R134a when I got it all back together.

One of the new hoses still had the R12 fitting on it, so I installed a "proper" R134a fitting for the quick disconnect.



The shop *should* be able to connect hoses to it, even if it doesn't have the quick-disconnect on it.

[1984GTTurboVert]

Are you absolutely SURE it was converted to r134?
What does your tag underhood say.
My tbird has those quick connectors on it but it was not converted to r134, but an r12 substitute called fridg12 by some shop in its life. Ofcourse i figured that out after i shot a can of r134 into it.
They stuck a blank sticker over the a/c label instead of a conversion sticker, they stuck that back on the firewall out of site where i wasnt looking for it.

[ITdude87]

Are you absolutely SURE it was converted to r134?
What does your tag underhood say.
My tbird has those quick connectors on it but it was not converted to r134, but an r12 substitute called fridg12 by some shop in its life. Ofcourse i figured that out after i shot a can of r134 into it.
They stuck a blank sticker over the a/c label instead of a conversion sticker, they stuck that back on the firewall out of site where i wasnt looking for it.

No - I'm not absolutely sure. Everything looks stock to my untrained eye.

Underhood tag is original and still says X-lbs of R12, I don't see any "conversion" stickers.

I have an invoice that says "R134 conv" from some years ago, but that's it.

[86MustangGtRob]

When I changed all the lines for my ac on my 85gt. I changed the pressure switch to match the 134 gas. The shop I brought it to put the quick release on my ac line.

[ITdude87]

I guess I'm looking for a more "explain like I'm 5" answer.

Am I understanding you guys correctly in needing to swap out parts to have it run with the current absence of R12? I have very rudimentary knowledge of how the AC system works and what needs to be done.

Or..

Can I just bring it to a shop and say 'charge it up', and they'll know what to do and be on my way?

[1984GTTurboVert]

Look around underhood for a conversion to r134a sticker. They are supposed to cover the old one and put on something indicating it was converted.
If you cant find anything underhood that says it was converted, assume it wasnt regardless of paperwork. Those quick connectors just screw on anybody couldve put those there for no reason at all.
The shop you take it to will ask you, and if you dont know and there isnt anything to tell them they will have to empty and flush it regardless, so extra cost and extra work.
If a shop did the conversion there should be something underhood to alert the next guy, if some guy did it in his garage there might be/might not.

Tldr, take it to the shop.

[Chuck W]

I guess I'm looking for a more "explain like I'm 5" answer.

Am I understanding you guys correctly in needing to swap out parts to have it run with the current absence of R12? I have very rudimentary knowledge of how the AC system works and what needs to be done.

Or..

Can I just bring it to a shop and say 'charge it up', and they'll know what to do and be on my way?

I mean, if you're unsure about how it all works, and don't want to mess with it, take it to a shop. It may cost you more if they have to investigate on whether it's been converted or not.

I've been accumulating tools to keep all of the AC systems working in our cars, so it wasn't much of a stretch for me.


I didn't replace stuff on my AC system because of the conversion. I replaced it because the car had been sitting for who knows how long with the AC hoses cut.
The compressor is original, and I just flushed it out before putting things all back together. The only thing I added for the conversion was the adapter fittings for my new hoses/gauges for R134a. The condensers are more efficient these days and the old one was dead anyway, so again, nothing special to do the conversion.

[ITdude87]

Thanks fellas.

I was reading your comments as those things needing to be replaced (hoses, condenser, lines, pressure switch....etc) for it to work with R134A, not for other unrelated reasons.

If it's just a matter of bringing it in to a buddies shop and doing a purge and fill, I think I'm golden from what I can ascertain. Not worried about cost, I just want it done properly.

I've never had to deal with a car this old that came with obsolete refrigerant, so this is a little outside of my wheelhouse as to what I need to be aware of and expect.

[Chuck W]

The pressure switch can be adjusted IF it's needed, but I didn't touch mine.

[bwguardian]

One can still find R12...

[KevinK]

Four seasons makes an R134 pressure switch.