My A/C is starting to struggle to keep up and I would like to re-charge the system. Can anyone tell me what I need to use? I dont think they make what was originally put in the system. Do I need to remove the freon in the system before adding more of whatever it is I need to put in it?

Thanks for any help.

GW
'86 SE v6

Find the leak first, recover the existing refrigerant in a legal and responsible manner (many AC shops will do this for free), and then fix the leak.

R-12 (the original refrigerant) hasn't been manufactured or imported into the U.S. since 1993 but it's still available legally; it's just expensive (~$100-$150 for a full charge). As an alternative, you can convert the system to use R-134a refrigerant ... or you can pay someone else to convert it for you. As an individual you can't legally buy R-12 any more (unless you have a "609 Certificate" from the EPA), so you will probably have to have a commercial shop evacuate and charge the system. Learn all you can about the process, buy some of the tools required, and next time you may be able to do most of it yourself.

[This message has been edited by Marvin McInnis (edited 06-16-2010).]

Thanks for the response. Do you have any suggestions to make finding the leak easier? They sell refrigerant with a tinting that shows where leaks are, but I do not believe that the refrigerant is compatible to my system.

GW
'86 SE v6

quote Originally posted by ghawiii: Thanks for the response. Do you have any suggestions to make finding the leak easier? They sell refrigerant with a tinting that shows where leaks are, but I do not believe that the refrigerant is compatible to my system. GW '86 SE v6

That is why you go to an AC shop to locate the leak as they have the equipment. To just refill an old system with 134a doesn't work. You need to evacuate the system chang "O" rings, shrader valve, fix the leak which may involve replacing the pressure lines, swap out the drier and maybe the compressor. People say they can do it for $200, my experience is that to do it right usually costs more like $1200.

R-12 and R-134a are not compatible. You absolutely cannot mix them! If you mix refrigerants anyway, no commercial shop is ever going to work on your car due to the strict regulations concerning "contaminated" systems; and if you don't tell them in advance, then you are responsible for all the resulting (very substantial) costs.

The AC shop will have an electronic "sniffer" that can locate most leaks pretty quickly. Probably more than 90% of all refrigerant leaks are in one or more of the rubber seals used throughout the system. A leaking seal in the compressor is difficult and/or expensive to replace, but most of the other seals in the system are simple, cheap O-rings. On the other hand, if the leak is due to a corroded condenser coil or evaporator coil, or a failed compressor, the system may or may not be worth fixing if you have to pay someone else to do it.

If you're going to do any of the work yourself, you need both access to a GM/Helm Factory Service Manual and someone experienced to guide you. The old saying, "Do it right or do it over" definitely applies to AC work.

[This message has been edited by Marvin McInnis (edited 06-16-2010).]

I agree,you may or may not have a leak.It may have slowly leaked out over time (probubley new O ring seals would help).You will need R-134a Ester oil conversin (with Ice, Brand Name at the bottom,not realley Ice) from autozone,look for the slighley higher price about $8,read the back sticker if you need to.A new Acumulator and filter.R134a refrigerant.If you have a leak AC UV Dye will help,but you will need a UV light. Then you would need a vacume pump to draw all the air out befor rechargeing.....Definatley a bit Complicated,have an AC shop do it.

Thanks guys. Looks like its riding around with the windows down for me...I was hoping that it would be something I could do on my own to save some money. But like Marvin said...I dont want to do it twice...not for that kind of money. I appreciate the repsonses.

GW
'86 SE v6

[This message has been edited by ghawiii (edited 06-16-2010).]

quote Originally posted by ghawiii: Looks like its riding around with the windows down for me...

... or you could sign up for an automotive AC course at your local community college. Not only will you learn how to do it right (knowledge you can use for a lifetime), but they will have professional equipment available in the lab/shop for you to use.

quote Originally posted by Marvin McInnis: ... or you could sign up for an automotive AC course at your local community college. Not only will you learn how to do it right (knowledge you can use for a lifetime), but they will have professional equipment available in the lab/shop for you to use.

Not a bad idea at all. I may just do that once I finish with the classes I am taking now...it has got to be better than biology!

quote Originally posted by ghawiii: Not a bad idea at all.

That's what I did, even though I already had a little AC experience and some of the basic tools. The tuition (a one-time expense) will still be a lot less than paying a commercial shop to do the work for you.

P.S. Some day you'll be glad you took Biology. Believe it or not, knowing a little Biology will make you a better automotive technician ... or whatever else you choose to do for a living.

quote Originally posted by Marvin McInnis: That's what I did, even though I already had a little AC experience and some of the basic tools. The tuition (a one-time expense) will still be a lot less than paying a commercial shop to do the work for you. P.S. Some day you'll be glad you took Biology. Believe it or not, knowing a little Biology will make you a better automotive technician ... or whatever else you choose to do for a living.

I am enjoying the classes...now that I am older (late 30's) I have an actual interest in these things...not like when I was in HS. I am actually working towards a degree in computer science. I do enjoy working on cars, but not when its a daily driver!

Even though I was educated as an aeronautical engineer, I have supported myself doing technical/scientific computer science stuff for most of my career. Years ago I had a contract providing software support the the Biostatistical Section at the FAA's Civil Aeromedical Institute. Do you think that my college exposure to Biology and Statistics may have come in handy on that job? Yes!!! The point is, you never know.

The R134 convertion does not require to change the O-rings if they are in a good shape.

I converted my GT87 system 2 years ago without any issue. Here is what I did
1) Change the ac compressor as it was broken
2) Change the condenser as it was leaking
3) Change the dryer
4) Let the system refilled with at and AC center

When I mentioned to the AC specialist the O-ring issue, he told me it was not necessary as long as there are in a good shape.
It was the case on my car

Hope this helps,

Bernard

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Bernard
Fiero V6 GT 1987 (Manual)

quote Originally posted by BL3200: The R134 convertion does not require to change the O-rings if they are in a good shape. I converted my GT87 system 2 years ago without any issue. Here is what I did 1) Change the ac compressor as it was broken 2) Change the condenser as it was leaking 3) Change the dryer 4) Let the system refilled with at and AC center When I mentioned to the AC specialist the O-ring issue, he told me it was not necessary as long as there are in a good shape. It was the case on my car Hope this helps, Bernard

Can I ask how much was the bottom line?

I don't pretend to know much about this, but a few years ago I had a car with an older freon 12 system. The A/C shop removed R12 and put in Red Tek; didn't have to change anything in the sytem, and it apparently cools better. Is there something wrong with this simple approach?

Rick

[This message has been edited by couldahadaV8 (edited 06-16-2010).]

The bottom line was 545$. Here is the detail
1) Condensor 220$
2) AC Compressor 185$
3) Dryer 60$
4) System refill with R134 80$

But as it is mentioned on this post, normaly you change R12 to R134a without modification.
However, I was adviced to change the dryer (cheap part anyway)

Hope this helps,

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Bernard
Fiero V6 GT 1987 (Manual)

quote Originally posted by BL3200: The bottom line was 545$. Here is the detail 1) Condensor 220$ 2) AC Compressor 185$ 3) Dryer 60$ 4) System refill with R134 80$ But as it is mentioned on this post, normaly you change R12 to R134a without modification. However, I was adviced to change the dryer (cheap part anyway) Hope this helps,

It definitely helps! Thanks!

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GW
'86 SE v6

took my 88gt to a auto shop. evac of old freon.,and added the new r-134. $120.00. no need to rebuild. after twenty yaers old freon went low on it"s own. just bought the car and they recharged it for me. only thing to change is the quick disconnect. two of them. high end and low end. still nice and cold for two summers now.

quote Originally posted by winger1955: took my 88gt to a auto shop. evac of old freon.,and added the new r-134. $120.00. no need to rebuild. after twenty yaers old freon went low on it"s own. just bought the car and they recharged it for me. only thing to change is the quick disconnect. two of them. high end and low end. still nice and cold for two summers now.

Thats what I am praying for. The A/C still works okay, just seems like it should be better. The car has been well taken care of all its days. But if there are leaks I want to make sure I fix them.

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GW
'86 SE v6

To properly convert a system from R-12 to R-134a, you must at least do the following:

1) Locate any leaks in the system.

2) Recover any remaining R-12. As stated earlier, many AC shops will do this for free.

3) Fix any leaks found in step #1.

4) Replace the accumulator (see #5 first) and orifice tube.

5) Add the proper amount of PAG or ester oil to the accumulator immediately prior to installing it.

6) Install R-134a service port fittings.

7) Evacuate the system to remove air and moisture, and to check for leaks. Fix any leaks before proceeding.

8) Charge with the proper amount of R-134a (by weight or liquid volume, not by pressure).

9) Affix the EPA-required conversion label

Of course, this assumes that the compressor is healthy and that neither the condenser nor the evaporator is leaking. Total cost of parts and materials should not be more than about $100. For another $100 or so you can buy a suitable vacuum pump and a service manifold and gauge set from Harbor Freight.

Both GM and the EPA agree that you do not need to replace hoses or O-rings, except that O-rings should always be replaced whenever a connection is opened up. Similarly, they do not recommend flushing the system unless there is debris in the system (i.e. the compressor is self-destructing or the desiccant bag in the old accumulator has ruptured). You will know if there is debris in the system as soon as you remove the old orifice tube.

[This message has been edited by Marvin McInnis (edited 07-01-2010).]

search freeze 12 if your just low --- if completely empty do a 134 conversion -- either way be sure to mark you system and use the correct conversion fittings

Freeze 12^* is a legal if imperfect alternative to R-12, but once you use it no reputable AC shop will ever be willing to touch your car again. And if you don't tell them, then you are responsible for all their costs associated with disposing of the "contaminated" refrigerant and repairing/replacing "contaminated" equipment. IMHO, it's not worth it.


^*Freeze 12 was listed as of June 3, 1997 under the EPA SNAP Program as an acceptable substitute for R-12, "... subject to (unique) fittings, (proper) labeling, no drop-in, and compressor shutoff switch use conditions." According to the EPA, Freeze 12 consists of 80% R-134a (HFC) and 20% R-142b (HCFC).

[This message has been edited by Marvin McInnis (edited 06-17-2010).]

just putting this out there.....
http://norfolk.craigslist.o...earch/sss?query=r-12

quote Originally posted by Marvin McInnis: To properly convert a system from R-12 to R-134a, you must at least do the following: 1) Locate any leaks in the system. 2) Recover any remaining R-12. As stated earlier, many AC shops will do this for free. 3) Fix any leaks found in step #1. 4) Replace the accumulator (see #4 first) and orifice tube. 5) Add the proper amount of PAG or ester oil to the accumulator immediately prior to installing it.. 6) Install R-134a service port fittings. 7) Evacuate the system to remove air and moisture, and to check for leaks. Fix any leaks before proceeding. 8) Charge with the proper amount of R-134a (by weight or liquid volume, not by pressure). Of course, this assumes that the compressor is healthy and that neither the condenser nor the evaporator is leaking. Total cost of parts and materials should not be more than about $100. For another $100 or so you can buy a suitable vacuum pump and a service manifold and gauge set from Harbor Freight. Both GM and the EPA agree that you do not need to replace hoses or O-rings, except that O-rings should always be replaced whenever a connection is opened up. Similarly, they do not recommend flushing the system unless there is debris in the system (i.e. the compressor is self-destructing or the desiccant bag in the old accumulator has ruptured). You will know if there is debris in the system as soon as you remove the old orifice tube.

Marvin is spot on. It was originally believed that old o-rings and hoses had to be replaced with a different material because R-134a particles are smaller than R-12 and thus they would migrate through the hoses and seals themselves. This proved false, as the refrigerant oil impregnates the hoses and seals over time and prevents the R-134a from being able to escape. The only suggestion I would make is to use Ester, NOT PAG - Ester is specifically designed for conversions from R-12 to R-134a and does not react with old mineral oil. If I recall, PAG is much more sensitive to mineral oil.

Whatever you do, you MUST replace the accumulator and orifice tube. Together its about $25 in parts and your system WILL fail without these replaced. They're not that hard to replace either - both are easily accessible near the spare tire. Don't believe the crap these "retrofit kits" claim, especially the ones that have "drying agents" and "leak sealers" mixed in with the refrigerants. When you replace your accumulator and properly vacuum the system, all of the moisture will boil off and there is no need for "drying agents" that will only reduce the efficiency of your system. Leak sealers are worse and, in addition to reducing cooling performance, can clog the orifice tube.

FYI most auto parts houses have vacuum pumps that you can rent (for free).

quote Originally posted by masospaghetti: The only suggestion I would make is to use Ester, NOT PAG - Ester is specifically designed for conversions from R-12 to R-134a and does not react with old mineral oil. If I recall, PAG is much more sensitive to mineral oil.

I thought so too, but now I'm not so sure. I recently came across this 2005 TSB from ACDelco. It is adamant that only PAG is approved for use in GM/Harrison/ACDelco compressors: "There are no Ester lubricants approved by ACDelco for retrofitting R-12 systems or for use in R134a systems." (Emphasis present in original.) Even though the TSB is only 5 years old, further research is probably indicated.

quote FYI most auto parts houses have vacuum pumps that you can rent (for free).

I have my own vacuum pump, but that's still good to know. Thanks.

[This message has been edited by Marvin McInnis (edited 06-17-2010).]