[b_chandler]

Well then you better call the freon police because every automotive retail outlet and even the local Walmart are selling R134A
to any idiot with cash, check or credit.

Now back to reality, Yes the system was originally furnished with R12. The compatibility problems between R12 and R134A stem from the compressor oil and the dessicant used in the dryer. I converted my '91 Mustang with this in ming and it is still happily using the original compressor.

By flushing the system to get rid of all of the old oil and draining the oil from the compressor, you've cleared one hurdle. The other hurdle is simply a matter of changing the dryer to a R134A compatible unit. They didn't ask for my license when I bought those parts either BTW.

Okay so now we have a clean system with the old oil replace and new PAG oil in the proper places (RTFM helps here). Now pull a vacuum on the system, check it for leaks, resume the vacuum to boil of residual moisture. When that's done, charge the system using the guages you bought without a license at the local auto parts store and that refrigerant you bought without the same license.

Done.

Now if my picture shows up on the post office wall after doing half a dozen or so of these conversions on both GM and Ford vehicles, well then I'll do the honorable thing and turn myself in.


I gather your a professional and you worked hard and paid a few bucks to get your license that says you can recover, recycle and deliver refrigerant. Congratulations. Rock ON!

Most of the time, people look to do an R134 conversion when the R12 system craps out, which typically means the refrigerant has already left the system and widened the hole in the ozone layer unbeknownst to Joe Carowner. All he knows is that his A/C quit, and the local Goodwrench is quoting prices with and without vasoline to get his vents to blow cold so he looks into DIY and possibly ends up here with a few questions.


R12 is like leaded gas. Sure you can still use, but why? It's more expensive and hard to come by and the new stuff gets the job done.

Let's agree to disagree and get back to helping these kids keep their cars running so they don't have to ride their bikes to school.

[Mike89]

The system was indeed designed to use r-12, But converting is what all the pros say to do because r-12 is so expensive. The last time I looked r-12 was 120.00 a can were as r-134a is like 6.00 a can at wally world. I had mine converted and so has many others with no problems. only cost 180.00 were buying the r-12 would have cost 360.00.

You do not need an A/C license for r-134a.

[oldwolf99]

Originally Posted by TOM RENZO

Yes stay R12. The system was designed for R12. And a lot of fords dont like to be converted. The compressors will fail in a relitively short time. R12 is still available. The only thing is the system must be leak free. You dont want to waste it on a system that leaks. Remember an AC licence is required no matter what freon you use.

Then can you answer me a question? Why does Walmart, Autozone and every other parts supplier sell cans of 134a over the counter and on the shelf to anyone wanting it with no questions asked much less a liscense? If memory serves, only R12 requires a liscense OR sometimes if a person asks to buy a 30lb cylinder. The expansion valve looks like this
http://info.rockauto.com/getimage/ge...ts%5C38608.jpg
Just FYI.

[TOM RENZO]

Jan 1 1992 Mandatory use of certified recycling equiptment when servicing automotive AC systems. Must be on site.
July 1 1993 prohibits venting of R12
Aug 12 1993 Reclaim equp must be registered with the EPA
Nov 14 1994 Mandatory licensing for ac repair
Nov 15 1995 Prohibits all venting of any freon
The fines for non compliance is 27,500 dollars
Purchasing of HFC134a is perfectly legal. But you cant put in in a system without a licence or the proper equiptment on site
Yes i am a perfessional with a licence.
Ford compressors dont have the correct seals that are compatible with an HFC 134a oils. Unless they are designed for that freon. R12 is not that expensive any more. I sell it installed all day for 30 dollars a pound. Ford cors need app 2 1/2 lbs of freon. Total cost for freon would be 75 dollars.

[TOM RENZO]

The mustang if equipped with factory air does not have an expansion valve. It's a CCOT system.

[b_chandler]

Someone needs to tell my compressor to start leaking. It apparently missed that memo. And yes, the Ford systems do use an orifice tube rather than an expansion valve ala GM. The mustangs in particular have an orifice tube that is permanently installed in the line. To change the orifice tube you have to replace the line. No big deal really.

As for the rest, well....mea effin' culpa.

[TOM RENZO]

Hi chandler i am not ragging on anyone. I respest DIY and help them all the time in my shop. But if anyone is performing AC service (and i dont object one bit ) they should have some knowledge of the system. Just dont make it known to to many people and do it in your garage. The fines are outrageous. Hay you beat the odds on that compressor. Be COOL Tom

[b_chandler]

No harm no foul. As a DIY'er, I respect the professional and lean on them from time to time to separate my head from my rectum. I like helping people too and I'm quick to send someone to a pro if I get the feeling they're in over their head. I also know my limitations and defer to the local shop when it's either outside my skill set or outside of my toolbox.

Everything's chilly! Mustang's all nice and frigid and after an all day assault two weekends ago on the evap core in my Dodge Ram, it's all frosty too.

[TOM RENZO]

Dodge RAM that one is a killer. Lots of beer pizza and parts all over the place. Been there on that one several times DUDE. Its nasty and a lot of hours.

[oldwolf99]

Originally Posted by TOM RENZO

Jan 1 1992 Mandatory use of certified recycling equiptment when servicing automotive AC systems. Must be on site.
July 1 1993 prohibits venting of R12
Aug 12 1993 Reclaim equp must be registered with the EPA
Nov 14 1994 Mandatory licensing for ac repair
Nov 15 1995 Prohibits all venting of any freon
The fines for non compliance is 27,500 dollars
Purchasing of HFC134a is perfectly legal. But you cant put in in a system without a licence or the proper equiptment on site
Yes i am a perfessional with a licence.
Ford compressors dont have the correct seals that are compatible with an HFC 134a oils. Unless they are designed for that freon. R12 is not that expensive any more. I sell it installed all day for 30 dollars a pound. Ford cors need app 2 1/2 lbs of freon. Total cost for freon would be 75 dollars.

Tom - Your quotation of EPA regulations is correct. I am also certified and have 20+ years experience on all makes and models. The reclamation of freon on registered equipment (the equipment is designed and registered by the manufacturer with the EPA) is for systems that have freon left in them when they arrive or for reclaiming any freon used for testing purposes for finding leaks. The average Joe cannot purchase R12 anymore.

They do sell 134a compatable compressors for mustangs of this vintage. I reccomend them with new O-ring sets and receiver driers on these types of conversions. This is especially true if they plan on keeping the car for a long period of time. If they are not then by all means keep it R12.

My point was that NO ONE had mentioned flushing the system or the need to evac the system. Much less the replacement of parts where the R12 oil will accumulate or catch which will cause catistrophic failure of the A/C compressor.

If a harry-home-owner wishes to change an R12 system to 134a and the system is VOID of freon then no recycle machine is required. Simply replace the previously mentioned parts (making sure that the correct type and amount of compressor oil is in the system.) and have the system placed under vacuum to verify no leaks and to remove any excess moisture. All that is left is charging as needed.

If they don't have gauges, pressures chart and a vacuum pump it is a null point. The job cannot be done so it will work. I agree with you that a professional is the way to go. However, some people cannot afford it and in those cases I try and steer them to best practices.

[TOM RENZO]

Hi 99 Jan 1 1992. Certified reclaim machines must be on (prem). 99 have you got your new certification yet. The test is like 6 hours and deals with all freons. The new 1234a that will show up in 2011 is going to replace HFC134a. I hold a master licence not a MACS license. You are totally right how does the DIY flush and clean the system if they dont have a licence??? You nead nitrogen and 22 to leak test properly. In 45+ years in the business i have seen many a system not lesk under vacuum that will leak under preasure. Also if you dont have a vacuum pump that can go down to 29.6 inches of mercury the pump will not boil off the moisture. I here you 99 its that they are stuck between a rock and a hard place. We now have to have very expensive freon identifiers now. If we try to dispose of blends its $600.00 for a 30 lb jug. Fixing AC systems legal and correct is super EXPENSIVE for people in the business. Thanks 99 TOM

[TOM RENZO]

One other thing 99 i am at an advantage and saw this freon scam coming. To date i only have 700 lbs of R12 left. I bought it when a 30 lb jug was 30 dollars. At one time i had 2 full pallets of 50 lb jugs. I even have the 1 lb cans left. I have 2 cases of those. But R12 is cheap now and is seldom used anymore. I will probly never run out of the stuff. I get alot of collector car guys that still need it. If they have factory AC they loose point for a conversion at a show. Thanks TOM