Question about R-12 Refrigerant

[deevergote]

A proper conversion shouldn't be any less effective or reliable than the original R12 system. If it doesn't work well, it was either done incorrectly, or poor quality components were used.
Ideally, the compressor, condenser, and every AC line should be replaced with brand new parts, and the parts should be absolutely clean. Anything less would result in contamination, and therefore poor performance and eventual failure. There's a reason why a proper conversion costs so much.

[Raf99]

R12 refrigerant was colder than R134 by nature so I can see keeping the R12. I wish i could do the same.

Link

[deevergote]

I'm still considering one of those "R12 compatible" recharge kits for the Miata. It doesn't work at all now anyway, so what harm could come from pumping it full of something that may or may not work well?

[H311RA151N]

My 93 LX has R12 A/C. It kicks the heck out of R134A in our cars. I've done it both ways. Converted Hadsys to Denso etc. I'm so thankful for my R12 system! Especially at this time of year.

[hiptech]

I understand the ports are different and it may be harder to find proper new gauges fror R12 unless you can still locate a decent old set that hasn't dry rotted....

BTW wasn't there a lot of issues with converting R12 to R134a? I seem to recall problems with leakage due to molecular compatibility with hoses as well as the cooling effeciencies. Has all that been resolved now?

[deevergote]

R134a and R12 are not compatible. Any R12 remaining in the system will not react well with R134a. Convert correctly, and the system will function as if it were made for R134a originally. Convert incorrectly, and you'll have issues. Any issues reported are likely due to improper conversions.

[Raf99]

Ya, i've read many posts which claim they are not compatible. The oils don't mix with each other and cause contamination, degrading of rubber seals, and I've even read somewhere about explosions.

Yet.... i also read and know people who simply dumped R134 in and it's been working fine for years. I think to know the real answer you'd need a A/C professional in here as it sucks when all you hear is "Well i did it and I have no issues"....

I think the user who did a full conversion may be able to help you. He states:
"So I recently I decided to do the retrofit for my CB7 and found a few kits at Wal-Mart and a few local parts stores like Auto Zone and Checker that claim to convert the cars A/C system from R12 to R134a. Only to find out that if the two mix it turns into a little something the pros in the A/C biz call the “Black Death” which sort of looks like engine oil crud on the inside of the compressor and all the components associated with the air conditioning and is sticky as hell and is pretty much impossible to remove. The only way to do properly is to replace all the old R12 O-rings with R134a O-rings, replace the receiver/drier, and flush the whole system and fill it."

http://www.cb7tuner.com/vbb/showthread.php?t=165508

[deevergote]

^that would indeed be the correct way to do things.
I wonder where that guy went. I always liked his posts. Haven't seen him in a while!

Anyway, you're right about a professional, though I know many pros that love to take "good enough" shortcuts. I'm astounded how many pros actually believe old wives' tales and absolute nonsense. I've learned to be skeptical of any professional until I see they genuinely know what they're talking about. Technically, "professional" just means you do it for money! It doesn't mean you haven't been doing it wrong for the last 25 years.

[GTRON]

There's a lot of controversy, obviously.

I did it the cheap easy way, with the exception of replacing the expansion valve, and emptying the old oil out of that little radiator thing. I replaced any O-rings that I disturbed, vacuumed the system, made sure I didn't have any leaks. Filled it up and it's been working well for two years now. I used "PAG" oil that is compatible with both r12 and r134a. It was hard to find a exact amount of PAG oil to use with R134a, so I ended up guessing, and it worked! haha.

That's what I did anyways, taking out every single A/C component out of the car (to flush it) is no small job, and just I didn't want to do it. That would guarantee that the system would work properly for a long time though, hence it being the "right" way to do it.

[GTRON]

Ya, i've read many posts which claim they are not compatible. The oils don't mix with each other and cause contamination, degrading of rubber seals, and I've even read somewhere about explosions.

Yet.... i also read and know people who simply dumped R134 in and it's been working fine for years. I think to know the real answer you'd need a A/C professional in here as it sucks when all you hear is "Well i did it and I have no issues"....

I think the user who did a full conversion may be able to help you. He states:
"So I recently I decided to do the retrofit for my CB7 and found a few kits at Wal-Mart and a few local parts stores like Auto Zone and Checker that claim to convert the cars A/C system from R12 to R134a. Only to find out that if the two mix it turns into a little something the pros in the A/C biz call the “Black Death” which sort of looks like engine oil crud on the inside of the compressor and all the components associated with the air conditioning and is sticky as hell and is pretty much impossible to remove. The only way to do properly is to replace all the old R12 O-rings with R134a O-rings, replace the receiver/drier, and flush the whole system and fill it."

http://www.cb7tuner.com/vbb/showthread.php?t=165508

There's different types of oil if I remember, some that work with just R134A, some that work with both.

Explosions are from people using R12 substitutes that are basically propane, or something like that. I wouldn't ever do that

[deevergote]

All refrigerants are flammable to some extent, but the propane and butane based R12 "compatible" things are typically a greater risk. Apparently those things work well, but a leak could result in a bbq.

[GTRON]

All refrigerants are flammable to some extent, but the propane and butane based R12 "compatible" things are typically a greater risk. Apparently those things work well, but a leak could result in a bbq.

*But a leak could result in you being BBQ'd

[F22Chris]

Do it right > do it thrice.

At least let a shop or reputable place add the oil & gas after you do the rings, expansion valve, drier etc.

It'll literally take them 30 minutes to vacuum and refill.

Most everything is combustible.

[H311RA151N]

In regard to the oils and refrigerants compatibility.

Ester works with both R12 and R134.

Mineral is for R12.

And PAG is R134A.

PAG and mineral don't mix but ester works with both.

The last CB7 I converted to R134A I used ester. Just in case I missed some mineral oil somewhere although I removed every component and line from the car and flushed it with solvent.