We bought our 1990 4Runner, 3.0 Auto in 2008 and at the time the air conditioner was amazingly cold. I remember the seller mentioned it had been converted, but my wife remembers the seller only said it had been serviced. Right now it's pretty weak and needs service. Looking around the system I don't see where any stickers were affixed to indicate it was upgraded to R134 and the accumulator has a sight glass. Is this enough information to be comfortable knowing it still has R12 in it? Are there any physical connections or fittings that would give away an upgrade?

Whatever happens with this thing is almost certainly going to be done by me personally. I did many air conditioner services back in the 1980's and coming into the 90's, but what I remember from it ahs been lost to time and was definitely before R134.

Thank you in advance

 

I believe the R-134 fittings are different than R-12. I'd bet it's R-12. I still run R-12 on my 86 Toyota truck. One of the valves has a slow leak. I use a metal valve cap with an internal rubber seal and specific refrigerant thread sealant to pretty much stop it. It needs a small charge about every 3 to 4 years. It will blow 38 on recirculate which is almost as good as the 34 when it was new. You can buy cans of R-12 on Ebay at a reasonable price. I have 2 cans as backup.

.

 

Yep, the fittings on the charge ports are different.

 

ThanX guys.
I sent an e-mail to the seller, someone I still kind of know and he is pretty sure he only had it "topped off". Looking at the fittings and they all look as old as everything else on it, so I'm going to presume nothing has been changed. I'll get some R12 for the time being.

 

The ports are very different; you can find some photos here: Note that high and low pressure ports are different; for R12 high and low are the same. The sight glass can be retained through a conversion; it doesn't work anymore, so you should black it out with paint, but that might not happen. Just like the sticker (and, for that matter, the correct ports) might not happen.

It is illegal to buy R12 without the correct license (Section 608 Certification) (or to sell to someone without the license) https://www.epa.gov/section608/refri...es-restriction eBay has lots of listings with the phrase "R12," but followed (eventually) with "replacement." (E.g., Envirosafe Arctic Air, which is mostly propane, also illegal to use). I did see one listing claiming to be real R12; the $46 (!!) can was rusty, so maybe? You'll save yourself a lot of grief to just convert to R134a (legal to buy and use) and be done with it. https://www.yotatech.com/forums/f116...-r134a-284801/

The biggest problem for DIY A/C work is the need for refrigerant recovery. Find yourself a friendly A/C shop that will recover whatever is in there now and hand it back to you. Once you've got it all buttoned up you can recharge it yourself (as long as you are careful).

Don't forget to use UV dye; either in the PAG, the refrigerant, or just added straight. If you ever get a leak (even a slow one) it will be much easier to find.

Good luck!

 

There are two ways to convert- the 'quick away' and the "factory way,"

The quick way just evacuate the R-12,clean the system of R-12 oil, add new fittings, R-134 oil, and R-134. Some old R-12 compressors can't handle the higher pressures required for R-134 and will need to be replaced as will the dryer. It's a cheaper way. Heard good and bad results doing it this way.

The factory way will yield better cooling, but its expensive as new AC components are needed. There are some important parts you will need in order to perform this conversion. These include:

• Compatible AC compressor (already discussed)
• AC Flush/ Service kit
• Green O rings for the R134a
• R134a port adaptors
• Complete HNBR O-ring kit for your vehicle
• R134a pressure switches
• R134a orifice tube
• New R134a accumulator/dryer
• R134A Retrofit Label
• New hoses compatible with R134A
• New barrier style hoses for pre-1990’s vehicle

1st I'd add dye to check for leaks. If none, then I'd do a recharge for $40 and go from there. You don't need to evacuate if you have a set of R-12 gauges. You can legally buy real R-12 online without a 608 Cert if you are buying it for a licensed AC mechanic to install. Or go online and get a 608 Cert as I did. It's ridiculously easy and a joke, but you are legal. Never had any Ebay seller of real R-12 (DuPont, Serco) ask for proof of a 608 cert.

If it still doesn't cool then you probably need to replace bad parts and a conversion would be warranted.