92 Corolla A/C compatable with R-134a?

[TOKFLA]

I have been spending some time trying to get the A/C working on my 92 Toyota Corolla (4AFE). It actually got to the point where it was pumping some cool air for a while but now it is not. My question concerns the compatibility of this A/C with the present R-134a refrigerant available. I was talking with someone tonight who said it was not and probably only compatible with the original freon 12. Does anyone have the experience with this to know for sure? Do I have to scrap my original setup for a total upgrade?

[SCT]

Nope. Just get the R12 pumped out, vacuum the system including sucking out all mineral oil, and refill with R134A and PAG oil. The only thing you may need are new seals/ o rings, but if it works, it works. Mine has been working fine!

Also, you'll need the R134A adapters (R134a Retrofit). R12 are screw on fittings, R134A are just bearing lock fittings. Available at any auto part store for a few bucks.

[TOKFLA]

Thanks. I already went through a couple of cans of R-134a with the little pressure gauge set up and adapters but I suppose the system is not maintaining it's pressure. What do I have to do to vacuum the system out and where are the seals and o-rings? Do I even have to vacuum it all out since it all drained itself?

[90 GP]

In your case this really isn't a DIY repair. The oil used in the R12 vs. R134 is different. That's why it's necessary to vacuum down the system before changing over to R134 and possibly replace some seals if necessary. You also need a dual pressure gauge to see both low and high pressure readings to see if you have a problem with leaks, overfilling or a bad compressor. If you have leaks you need to verify were it's coming from (condensor,evaporator or hoses/seals).Take it to a reputable shop that has all the equipment necessary to fix it.

[TOKFLA]

I presume DIY is "Did It Yourself"? I can not afford too much at this moment but I am so in need of some cool air. I think I had the proper high pressure hookup that I left 1800 miles away and now only have the low one..It was holding pressure but I think I left the Refrigerant install adapter on while traveling across country and that leaked. There is a lot to learn about these things...Thanks

[90 GP]

Most of the (Do It Yourself) recharge kits only have the one gauge on can that hooks to the low pressure line (not the high side) . To do it properly you need the dual gauge with a charging port in the center. You have to put in the correct ammount of charge with oil so the gauge readings on both sides are to specs. You can also admit moisture into the system if you have a leak which can really damage things and that's why it's necessary to have system put on a vacuum prior to recharging. That's why I suggest taking it to a shop.

[SCT]

Yea, vacuuming is necessary. Any moisture cannot drain out. By vacuuming, you're basically lowering the boiling point of H2O and pretty much vaporizing it. Also, it vacuums all air out. Moisture and air would cause faults in the A/C system.

I would prefer you go to a shop, too.

[TOKFLA]

Yup, I'm going to give this all a try and hopefully rid me of these sweat drenched clothes and broiling cerebellum....Thanks

[Flashmn]

Not to mention the way the compressor oils and works is different in R12 and R-134a, so dont expect a very long compressor life...