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Discussion Starter #1
Well, I need to charge the AC on my 1984 Cougar LS 3.8 V-6 but it has never been converted over to R-134. How much of an issue is this going to be to get changed over?
 

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Does it still have some charge? Has it been opened to the atmosphere?

If opened, or with no pressure at all:

Start off by dismantling it enough to pressure flush the cores (evap and condensor) and the hoses. Plan on replacing the orifice tube. IDEALLY - you replace the receiver/dryer or accumulator with a new one that's rated as R134a compatible. You also lube it with compatible refrigerant oil. The compressor needs to be pulled, drained, and reoiled. You then seal the system up, pull a full vacuum on it, let it sit for at least 30 minutes with the full vacuum, then charge it with (at first!) about 75% of the charge of R134a as it would have taken of R12.

Be sure to check the cycle chart in the service manual for that car to determine when it's fully charged.

If you're lucky enough to have a sight gauge, you don't want to go to no bubbles (please, the A/C gurus correct me if I'm wrong!) but neither do you want a white froth.

I'd suggest googleing for suggestions on exactly how much to use.

RwP
 

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AFAIK, the steps you are SUPPOSED to take:

1) Use a vacuum pump to pump out all the old R-12 refrigerant.
2) Replace orifice with correct size for R134
3) Install new O-Rings
4) Install R134 connectors on old R12 connectors
5) Fill with R134 & add appropriate amount of R134 oil
6) Finish off with pretty new blue and red caps.

These kits are hard to find and should be done be a professional shop, not the consumer. We don't do a lot of these, so there may be more steps and someone more experienced should speak up if that is so.

Sorry Ralph, didn't know you already spoke up, but I'm pretty sure Dan (who does all the a/c stuff at our shop) doesn't take all those steps!
 

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You will want to replace the accumulator as it contains a desiccant that removes any stray moisture within the system. Once it's exposed to the atmosphere it becomes saturated and needs to be replaced. Use PAG-46 oil for 134a.
 

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You will want to replace the accumulator as it contains a desiccant that removes any stray moisture within the system. Once it's exposed to the atmosphere it becomes saturated and needs to be replaced. Use PAG-46 oil for 134a.
Now, I have done that and seen Dan do it, too! :thumbsup:
 

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Sorry Ralph, didn't know you already spoke up, but I'm pretty sure Dan (who does all the a/c stuff at our shop) doesn't take all those steps!
Well, the logic given to me was:

1) You flush the cores and the hoses because any R12 lube can damage R134 systems.

2) You want a new receiver/dryer or accumulator because of the dessicant.

3) New orifice, check - different rates.

4) New cycle switch to allow for the different cycle pressures of R134a from R12.

5) And last but not least, drain the compressor so that none of the old R12 compatible oil gets into the system.

Not saying it's always needed, but that helps to avoid some of the sudden black-death syndrome.

RwP
 

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Well, the logic given to me was:

1) You flush the cores and the hoses because any R12 lube can damage R134 systems.

2) You want a new receiver/dryer or accumulator because of the dessicant.

3) New orifice, check - different rates.

4) New cycle switch to allow for the different cycle pressures of R134a from R12.

5) And last but not least, drain the compressor so that none of the old R12 compatible oil gets into the system.

Not saying it's always needed, but that helps to avoid some of the sudden black-death syndrome.

RwP
Sounds logical to me :) :thumbsup:
 

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Discussion Starter #8
Cool!!! Thanks for the information. This has never been open to the air and it does have just a bit of charge left in it as it cycles when you turn the AC on. I have a friend who has all the equipment to vacuum and charge so I will do the mechanical work and let him do the technical work.
I will keep this info!!! Thanks!
 

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My father does HVAC work and he removed the old R-12 out of my 93 and then added R-134a. Now we didn't bother changing the old fitting to the new style so anybody looking at it would assume that it still had R-12.
 

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About two years ago I didn't know jack about A/C's, about that time I was licensed to handle freon after taking tests through my job so I started servicing A/C's but not doing any repairs and frankly not knowing jack about the A/C system. I finally took a class a year ago because of all of my questions and concerns I had about various components, retrofits, adding oil, draining oil, freon types and brands, sealants, methods of charging, the charging circle, freon state, etc....

I now know enough about it to give you my professional $0.02, repair any and all leaks yourself after having the freon properly evacuated. Please do not vent R-12! Take it to an approved shop. Have it professionally charged with R-12. R-12 systems really were never made to work with r-134a, r-12 cools better, no work has to be done converting it, no parts need to be changed. If it still cycles like you claim and doesn't lose it's charge within a year then I would just service it and refill it with the proper amount of oil and r-12. I would not convert it. If it does lose it's charge within a year or less I would repair any leaks on it, replace the dryer and orifice tube, and properly fill it. Cans aren't the proper way to fill any A/C system. I service A/C's professionally and see the retrofits and conversions frankly they suck. Pay the extra for R-12 at a shop, R-12 it isn't illegal, it's just illegal for YOU to buy it, any MACS cerified tech can buy it all day long.
 
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