1990 legacy a/c conversion to r134

[90LegAWD]

has anyone done a r134 conversion on a r12 equipped car?

what parts do i need to do this (besides a recharge kit)?

[90LegAWD]

aha! nevermind... i finally found the tutorial

http://bbs.legacycentral.org/viewtopic. ... nditioning

[91legacyman]

thats funny cuz i accidentally put r134 in my system nothing bad happened but my ac seems to blow cold as hell lol

[vrg3]

The retrofit procedure doesn't really consist of much more than charging up with R-134a instead of R-12... The rest of the stuff mostly just satisfies laws (putting adapter fittings on, placing a retrofit label on) or helps ensure longevity (replacing the receiver/drier, flushing).

[mikec]

So I could get a couple of cans of R-134a and the adapters and see what happens? My A/C hasn't worked since I bought the car over a year ago, but I don't really want to pay someone to figure out where the leaks are, or what might be busted. I'm guessing the refridgerant has leaked out, and the previous owner never got it recharged. But I'm worried moisture has gotten into the system, or the compressor is shot.

I thought you had to do the entire retrofit, which is why I've been putting it off. I really should just get someone to at least pressure test the system, and see what they find.

[vrg3]

Most of the "retrofit procedure" is part of any proper charging procedure. It is good practice to replace the receiver/drier any time the system is opened to atmosphere (and to replace rather than reuse its o-rings). It is a requirement that the system be evacuated prior to charging. It makes good sense to use the evacuation as a leak check. All the flushing and cleaning is just a good idea, but not strictly necessary. A retrofit of a working A/C system can actually be as simple as installing the fittings, evacuating, and charging.

So, Mike, you can't just get some cans of refrigerant and a hose and charge the system up. It needs to be evacuated first. And it won't be possible to properly evacuate the system without fixing the leak. And because it has likely been exposed to moisture, as you intelligently worry about, the receiver-drier should be replaced. All of these things would be true even if you were just going to charge it back up with R-12.

[mikec]

Thanks for clarifying that Vikash.

I had asked at the dealership about having it retrofitted, and they spoke of probably having to replace lines and such if the system hadn't worked for a while. I'll look for somewhere that can tell me if I do infact have a leak to atmosphere, and then do the retrofit properly after fixing that.

[vrg3]

You don't necessarily have to replace the lines... a flush is a good idea though. Brake cleaner can be used to flush.

It's easy to do a preliminary leak check -- just try to pull a vacuum on the system. If that works, then shut off the pump and see if the system holds the vacuum. You can usually hear the leak and locate it.