R12 to R134a conversion—Your experience, thoughts, concerns?

[Optimistic Paranoid]

Any shop can do AC work.  Not a dealer exclusive.

Not a dealer exclusive, no, but a shop needs specialized equipment to do AC work, and not all shops have it.  It's no longer legal for them to just let the old Freon escape to the atmosphere, they need a recycling machine that can suck the old Freon out and store it.

Regards
John

 

[LeeRevell]

As my E150 lacks the Compressor, it being replaced by a simple pully and the associated plumbing hanging loose, I have decided it would make more sense to rip out ALL the old OEM AC gear to save weight, and install a second HD alternator in that location. It would also give me a bit more room to use a larger starting battery.

 

[DelHighfield]

Any shop can do AC work.  Not a dealer exclusive.

The screw on adapters for 134 can be a leak issue.

Thanks

It worked!

 

[Canine]

Change the fitting on the low side manifold.Add ester oil as needed.Charge with 134 until the low side line sweats.Morally Flexible!I'll have to remember that one.

 

[Canine]

One other thing.Unless you find and repair the leak,don't pull a vacuum on the system.You will be sucking air into the system thru the leak.Auto ACs have a low pressure shutoff to prevent this happening during use.You can jump this switch out to prevent the compressor cycling during charging.

 

[ramblingvanman]

Look guys, AC is not magical. From what I have read so far on this site, most of the people here seem fully capable of doing the work. R134a is not a great refrigerant, but R414b seems to only be available in large quantities whereas R134a can be bought at wal-mart. That being said, a 125lb bottle of R414b is only $125. So, it is not completely unreasonable in price. Especially if you do a few repair jobs to recoup the cost.

 

[eDJ_]

I've converted a few cars over from R-12 to the 134A with the Kits I got at Walmart.   Didn't have a lot
of luck in the long haul.  You had to flush the Oil  (PAG or Esther) out of the system and change O-Rings
for best results and a bunch of effort and the compressors still locked up.

Of course the Parts Store Counter Salesmen's solution is to sell you a new Compressor which is designed
for 134A.  Just like your original but with all the components in it designed for 134A.  $$$$$

I'll mention these things and you can do whatever you wish.   eBay often has R-12 available.  Old cans
that are discovered in estate sales,  store liquidations, even bootlegged into the USA and sold on eBay.
You can get it if you want it. 

I haven't seen this mentioned so far but a neighbor kid I knew years ago has grown up and is now an
HVAC tech and tells me about a Legal "Drop In" for R-12 that he says is totally "legal" now.  It goes by
different names such as HC 12a,  ES 12a, or OZ 12a.   He says it is quite affordable and can be easily
purchased by anyone.

As for myself, I wouldn't risk ruining a good compressor again.

Read about it here in WIKI

https://en.wikipedia.org/wiki/HC-12a

 

[highdesertranger]

hum, there is no difference for an AC compressor for older vehicles that came design for R12 and one for 134A. you must, YOU MUST remove 100% of the R12 and it's oil. if you don't it will fail, if you do it will last just as long as any other AC system. you must remember R134 is not as efficient as R12. to get the same performance you must, I repeat YOU MUST install a fan on your condenser. or else your low speed AC cooling will be seriously compromised. besides you also need to replace all your O-rings, your receiver dryer, and your orifice tube. back in the day my shop converted hundreds of ACs. in fact we never recharged with anything but R134a and we had no major problems if we followed the above advice. just saying. highdesertranger

 

[Seeker]

I have converted several vans from R12 to134a in he past.  Most I have changed the compressor,dryer and orifice tube if it was full of crap.
I usually use the flush and then blow it out.  I have even used an air compressor to blow the flush from evaporator and condenser although that can put moisture in the system

I have a tank of nitrogen with a pressure  regulator and will than blow out some more with the nitrogen.

after installing the new parts and correct oil I fill the system with a couple hundred pounds of nitrogen and wait a while to see if it holds without leaks.  If leaking I find the leak with my ultrasonic detector that has a ear phone headset.  When the wand is anywhere near a leak it sounds like Niagara Falls in the headset.  The nitrogen also helps remove any moisture in the system.  I have gone past 200lbs with the nitrogen to find hard leaks but if you put too much pressure a seal could fail and a leak created.

If no leaks I let out the nitrogen and hook up the vacuum pump and let it run for at least an hour to get as much air out as possible.  Then I start installing the 134a Freon.  I sometimes get a bowl of hot water to set the Freon can in so it will install easier.  Sometimes you need to jump the low pressure switch so  the compressor will come on to help pull in the Freon.  I like to change seals to the compatible ones with the 134a but have sometimes left the old ones and not had any leaks for over 5 years at least.
A SEEKER

 

[ZoNiE]

Get the leak fixed first, then use Duracool. You can buy it online. The GMC Motorhome community has been using it with great success. The problem with converting to R134a is you have to replace ALL the hoses, as the older non barrier hoses from R12 systems do not contain the smaller molecules in the R134a well and eventually it all leaks out too. You also have to drain ALL the esther oil and you never get it all out.

Duracool (or Freeze 12, CFC12, etc. there are many) also is compatible with all the different oils already in use, including Pag.

Before anyone posts that duracool is flammable, yes, it is, but so is R134a.

 

[Almost There]

Can anyone tell me what my 2002 GMC Savana 2500 has in it?

If it already has the newer technology in it that's a good start.

The a/c doesn't work but for the few times that a/c becomes really desirable, it's not something I'm willing to put a whole lot of bucks in to right now.

 

[LeeRevell]

Good question?  Is there a certain "cutoff" year for the old R12 stuff, and the introduction of R134a"?  Or is this different for each make/model?

I think I found some answers.....

https://answers.yahoo.com/question/index?qid=20090704060726AAStMok

http://forums.macresource.com/read.php?1,95539,95549

 

[Almost There]

Good question?  Is there a certain "cutoff" year for the old R12 stuff, and the introduction of R134a"?  Or is this different for each make/model?

I think I found some answers.....

https://answers.yahoo.com/question/index?qid=20090704060726AAStMok

http://forums.macresource.com/read.php?1,95539,95549

Thanks for the links!

I had no idea that the type of refrigerant was changed over so long ago, here I was thinking that it was a post 2000 issue.

Obviously my 2002 was made long after the switchover date.

Now I just have to find a reputable a/c repair shop - might be a little tough up here and neither of my two  repair guys have any recommendations other than to roll down the window....

 

[LeeRevell]

Now I just have to find a reputable a/c repair shop - might be a little tough up here and neither of my two  repair guys have any recommendations other than to roll down the window....

That is what we down here call "Poor man's AC".....   add a 12 volt fan on the dash and you are all set! 
My E150 has no AC - most of the gear is there but the compressor is GONE, and in it's place is a basic pulley.  Soon I will rip it all out, save some weight and install the dash-mounted fan.  Did that on an old Dodge Ramcharger, and got by okay.

 

[Milk Hauler]

Just lots and lots of snow cones to stay cool.

 

[ZoNiE]

Good question?  Is there a certain "cutoff" year for the old R12 stuff, and the introduction of R134a"?  Or is this different for each make/model?

I think I found some answers.....

https://answers.yahoo.com/question/index?qid=20090704060726AAStMok

http://forums.macresource.com/read.php?1,95539,95549

1994-ish, give or take a year depending on when models changed . My newest R12 car was a 1993 Chevy S10 Blazer. My 95 Pontiac Trans Sport was R134a.

The earliest years had horrible performance, usually because of the hoses.

At least when R134a Phased in, rental cars in Europe started coming with AC...

France in the summer is not fun in an underpowered car without AC and tint, in Paris stop and go traffic... :dodgy: I was there a lot for work.