How do I know what refrigerant is in my system? - Page 2 - PeachParts Mercedes-Benz Forum

JHZR2 · #16 07-01-2009, 08:47 AM

Got it, thanks!

Makes sense... Ill have it evacuated and repressurized to 30-40psi, I guess?

So moisture + R12 oil = acid (potentially). But what is the consequence of R134a + R12 oil? Or, R134a+R12+R12oil?

I assume that since HC is miscible in the R12 mineral oil, that if that was used to "top up", that wouldn't be a big deal.

Also, say the R12 in there IS contaminated with HC or 134a, what is the correct procedure to collect it? It seems that the shops recover and perhaps resell clean refrigerant that they obtain. However, if it is contaminated, Im sure they still need to collect it, not just vent it to the atmosphere. Do they typically have a dedicated "catch can" for the refrigerant, or do they do something else?

Thanks!

tjts1 · #17 07-01-2009, 09:55 AM

Wow they really got you guys by the short and curlies with this AC fear mongering stuff. HC refrigerant can be safely mixed with either R12 or R134 but it's illegal to do so. No AC shop will want to touch it or they will charge you an arm and a leg to have it 'evacuated and safely disposed of'. If the car was converted to R134 by a shop then the rubber hoses had to be changed to barrier type, as required by law. If the hoses look old and crusty with lots of MB PNs all around then chances are your system was never converted. Whatever you do, don't have it converted to R134. Your wallet will hate you and the AC perfomance will be pathetic.

JHZR2 · #18 07-01-2009, 11:12 AM

I know that part fully. Ive gone through the full set of experiences on my w123s.

The best plan to deal with my unknown situation is what is important to me here... I want to go in as a fully educated customer.

Kestas · #19 07-01-2009, 01:09 PM

I imagine that a mix of r12 and r134 will mess up the phase changes (i.e., liquid to vapor) needed for a/c to work efficiently. Then there's the issue of oil compatibility. Some oils are compatible with both refrigerants. Most aren't. Compatibility means that the refrigerant will carry oil and circulate it throughout the system. Otherwise the oil just sits at the low spots and doesn't lubricate.

Converting to HC refrigerants is legal in many states. But it can only be done on r134 systems. It cannot be done directly from r12. An r12 system must first be converted to r134 (with proper quick disconnect fittings), and only then may it be converted to HC (at least that's your story when the a/c police ask you about it).

#20 07-01-2009, 05:31 PM

Putting any other refrigerant BESIDES R134a in a system having R134a fittings is a violation of Federal law.

tjts1 · #21 07-02-2009, 02:53 AM

The AC police is coming to take you away!

Kestas · #22 07-02-2009, 09:12 AM

Quote:

Originally Posted by LarryBible

Putting any other refrigerant BESIDES R134a in a system having R134a fittings is a violation of Federal law.

No, it is not a violation of federal law. It is a violation of state law where you live (Texas), but it is allowed where JHZR2 and I live (New Jersey and Michigan).

http://www.epa.gov/Ozone/snap/refrigerants/hc12alng.html#q9

JHZR2 · #23 07-03-2009, 12:03 AM

Evacuated, refilled with R12, now very frosty. The delta was about 2 lbs on a 2.9 lb system. Works great. Compressor cycles much more gently, and when the system is running, no hissing in the lines (indicative I guess of a phase change where there is not supposed to be one due to low pressure?). Held solid vacuum for over 30 minutes.

Will overhaul the system later this summer - wanted to get on the road with cool air.

No indication of 134a, and they evacuated the system no problem. Told me that lots of mechanics just charge some 134a onto R12 because it works to some extent. Not legal or right, just what they have seen done before. Kind of like a real lousy conversion, but where some R12 is in there (I suppose to keep the oil moving).

Anyway, it works beautifully.

#24 07-03-2009, 07:12 AM

Quote:

Originally Posted by Kestas

No, it is not a violation of federal law. It is a violation of state law where you live (Texas), but it is allowed where JHZR2 and I live (New Jersey and Michigan).

http://www.epa.gov/Ozone/snap/refrigerants/hc12alng.html#q9

I did not say that it was a violation of Federal law to USE other refrigerants. I said that it was a violation if you used other than R134a with R134a fittings installed. By Federal Law you are supposed to have the fittings installed that are appropriate for the refrigerant contained in the system. Additionally the system is supposed to be labeled.

This law is probably broken more often than the speed limit, but it is the law.

#25 07-03-2009, 07:15 AM

Quote:

Originally Posted by JHZR2

Evacuated, refilled with R12, now very frosty. The delta was about 2 lbs on a 2.9 lb system. Works great. Compressor cycles much more gently, and when the system is running, no hissing in the lines (indicative I guess of a phase change where there is not supposed to be one due to low pressure?). Held solid vacuum for over 30 minutes.

Will overhaul the system later this summer - wanted to get on the road with cool air.

No indication of 134a, and they evacuated the system no problem. Told me that lots of mechanics just charge some 134a onto R12 because it works to some extent. Not legal or right, just what they have seen done before. Kind of like a real lousy conversion, but where some R12 is in there (I suppose to keep the oil moving).

Anyway, it works beautifully.

OUTSTANDING!

In the future, don't even think about going away from R12 no matter what maladies might occur. You will always be better off repairing whatever goes wrong and staying with R12. R12 is now $20 to $30 a pound. Not that much more to keep the system working well while eliminating the chances of problems of conversion ill effects.

Matt L · #26 07-03-2009, 10:34 AM

Quote:

Originally Posted by LarryBible

I did not say that it was a violation of Federal law to USE other refrigerants. I said that it was a violation if you used other than R134a with R134a fittings installed. By Federal Law you are supposed to have the fittings installed that are appropriate for the refrigerant contained in the system. Additionally the system is supposed to be labeled.

This law is probably broken more often than the speed limit, but it is the law.

I read the law differently. Those are rulings (which carry the force of law) are the SNAP rules, which restrict replacement of ozone-depleting refrigerants.

If you are converting FROM 134a, you do not need to change fittings. At least, that's my reading of it. It's pretty much impossible to change the fittings on a factory-134a system, and I don't see anything about converting a converted system, as long as the original 134a conversion is not a "sham" conversion.

I'm not a lawyer and certainly not a judge though.

#27 07-03-2009, 02:36 PM

It's been a LONG time since I did my 609 test, but at that time I did read all the stuff, not just enough to pass the test. I can't tell you where in all that reading it was specified, but it was clear that the fitting had to reflect the refrigerant inside.

As I said before, no one pays any attention to these laws.

Matt L · #28 07-03-2009, 03:06 PM

Quote:

Originally Posted by LarryBible

As I said before, no one pays any attention to these laws.

How true this is. And this is a good reason to never touch a system unless you trust the owner, and the owner has a complete knowledge of the prior service done to his system. Or buy a refrigerant identifier. That's one tool that I do not own.

#29 07-03-2009, 05:07 PM

I don't have a refrigerant identifier either. That's why I just refuse to recover anything into my machines unless I REALLY know and trust who I'm talking to.

Kestas · #30 07-03-2009, 08:47 PM

Quote:

Originally Posted by LarryBible

I did not say that it was a violation of Federal law to USE other refrigerants. I said that it was a violation if you used other than R134a with R134a fittings installed. By Federal Law you are supposed to have the fittings installed that are appropriate for the refrigerant contained in the system. Additionally the system is supposed to be labeled.

This law is probably broken more often than the speed limit, but it is the law.

Aren't R134 fittings the proper ones to use for HC refrigerant?