Converting from R12 to R134

R

Ryan

CEO/Founder Nakslist.com
Joined
Jun 2, 2001
I know this topic has been beat to death but most of the post I have been reading are all over the place.
New car. Per records the AC system was replaced and charged in 2010. A few owners later.....guess there was a leak cause it no worky. Dont think Im gonna find some r12 in Hawaii or be able to afford it. If I convert it to R134 do I need to replace any hardware other than the port adapters? Had a 93 chevy truck done. Had a neighbor with the equipment draw a vacuum and put r134 in. Was really cheap. Can I just get a shop to suck out the old stuff and use a $20 orielly kit?
 
If it has already been converted, I would not consider going back to R-12. An R-12 system converted to R-134a will normally loose some refrigerant over time. The R-12 systems didn't use barrier hoses . The R-134a molecule is much smaller than the R-12 and it finds its way out of smaller leak paths. So even if the system is fairly well sealed, you may have to add refrigerant every year or so.

My 87 Regal T has been converted. I have my own Robinair Recovery Recharge station. I recover the system every year at the beginning of the season and recharge with the correct amount. Maybe overkill, but my AC blows icy cold and I already have the equipment.....why not?

Have a professional find any leaks and correct them. An electronic leak detector and/or fluorescent leak dye in the system are the two best ways to find your leak. If you use any "Kit" stay away from anything with "Stop Leak" additives. The stop leaks products react with moisture to seal the leak. They work short term but cause big problems long term. Be careful, lots of the consumer refrigerant products have the stop leak in them. Be sure to use a vacuum pump and pull a deep vacuum 28-29"Hg for at least 30 minutes before you recharge. This gets air and moisture out of the system.
 
turbodave231 said:
If it has already been converted, I would not consider going back to R-12. An R-12 system converted to R-134a will normally loose some refrigerant over time. The R-12 systems didn't use barrier hoses . The R-134a molecule is much smaller than the R-12 and it finds its way out of smaller leak paths. So even if the system is fairly well sealed, you may have to add refrigerant every year or so.

My 87 Regal T has been converted. I have my own Robinair Recovery Recharge station. I recover the system every year at the beginning of the season and recharge with the correct amount. Maybe overkill, but my AC blows icy cold and I already have the equipment.....why not?

Have a professional find any leaks and correct them. An electronic leak detector and/or fluorescent leak dye in the system are the two best ways to find your leak. If you use any "Kit" stay away from anything with "Stop Leak" additives. The stop leaks products react with moisture to seal the leak. They work short term but cause big problems long term. Be careful, lots of the consumer refrigerant products have the stop leak in them. Be sure to use a vacuum pump and pull a deep vacuum 28-29"Hg for at least 30 minutes before you recharge. This gets air and moisture out of the system.
Click to expand...
Dave, I am getting ready to put my AC system back in and wondering if I should get R12 or r134. If I use the stock lines, which I dont believe will be a problem, is there anything that you suggest that I do. Would love to discuss this with you sometime!!!!

Clint
 
The compressor does not cycle on and off. If it just needs to be topped off.......can I simply attach the hose and fill er up? Does the compressor need to be activated to suck in the new gas?
 
There is alternatives to r134 in the residential applications that is worth checking.

Also try the compressed propellant cans.

Sent from my SAMSUNG-SGH-I747 using TurboBuick Mobile mobile app
 
Ryan said:
I know this topic has been beat to death but most of the post I have been reading are all over the place.
New car. Per records the AC system was replaced and charged in 2010. A few owners later.....guess there was a leak cause it no worky. Dont think Im gonna find some r12 in Hawaii or be able to afford it. If I convert it to R134 do I need to replace any hardware other than the port adapters? Had a 93 chevy truck done. Had a neighbor with the equipment draw a vacuum and put r134 in. Was really cheap. Can I just get a shop to suck out the old stuff and use a $20 orielly kit?
Click to expand...

Flush the system and replace the dryer/accumulator and the orfice tube.
 
Found someone with some r12. About 10lbs for $25. Should I try to go back to r12 or try to add r134?
 
Ryan,

Here are my recommendations:
Leave it R-134a........why you ask?
  • If your system was retrofit with Ester oil and the mineral oil is still in there, you will effectively have a double charge of oil. That is a death sentence for your compressor!
  • R-134a is easy to get.
  • R-134a is relatively inexpensive.
  • R-134 is still being made in the USA.
  • R-134a works pretty good in most climates in our cars. (ok, in Very hot humid climates maybe its lacks a little bit, install an upgraded condenser and a better dual cooling fan package, that will help!)
  • The EPA is not requiring the phase out of R-134a
  • Your car has already been retrofit for R-134a
Replace your accumulator, ( that big black or silver can on the passenger side) it contains a desiccant, that keeps moisture out of your system.

Dave
 
When you say upgrade the condenser........do you mean get a new one or is there an upgraded aftermarket one? Also the better dual cooling fans.....is that the radiator electric fans?
 
I have not investigated (I live in Michigan and we get maybe 2-3 weeks where AC is really necessary), but I'll bet you can probably get a higher efficiency condenser for our cars. Yes electric cooling fans= fan on radiator. Move more air and you will improve condenser performance. These cars do OK when they are going over 15 mph or so, its when they idle in traffic on a Hot humid day that the performance is lacking.
 
Hot shot is a blended refrigerant and it contains Iso-butane= flammable. None of the refrigerants listed below have ever been used in Mobile HVAC applications.
Hot shot is 50% R-22 which is the smallest molecule of any refrigerant......... Home and Commercial HVAC used R-22 for years and they always have hard lines.....no flexible hoses. Why? Hard lines keep the stuff from leaking out.

If you think R-134a leaks fast, try this stuff. 50% will leak out really fast leaving you with the rest of the constituents.
Why use a blended or "drop in" refrigerant when R-134a works really well?

The info below is from HotShot's MSDS sheet:
Material: CAS Number Typical Wt. %

Chlorodifluoromethane (HCFC-22) 75-45-6 50%

2-Chloro-1,1,1,2-tetrafluoroethane (HCFC-124) 2837-89-0 39%

1-Chloro-1,1-difluoroethane (HCFC-142b) 75-68-3 9.5%

Isobutane (HC-600a) 75-28-5 1.5%

*Regulated as a Toxic Chemical under Section 313 of Title III of the Superfund Amendments and Reauthorization Act of

1986 and 40 CFR part 372.
 
I converted to 134 way back, but I'm switching back to 12. I found a stash of 12on craigslist cheap and gobbled it up. It's out there fairly frequently. Seems like not too many people want it anymore due to popularity of the conversion kits.

like this guy:
http://chicago.craigslist.org/nwi/pts/4264074168.html
not bad at all, $25 for 3 cans. Almost can't buy 134 that cheap at Autozone.

The 134 works OK, but not like the 12.

No small project though, and not cheap. New hose assemblies, all new seals, new filter drier, new orifice, new compressor, clean the old heat exchangers, fresh mineral oil. Could be done with fewer parts and more cleaning, but my system is just old and a bit worn out.
 
R134 will cool just fine for most climates if you charge it by the numbers and a P-T chart
 
Ryan, what is currently in the car? I quickly read through the posts, and I don't see anywhere in your first post saying that it is currently 134. I see where you talk of converting it to 134. If it still has R12 I would personally leave it. Like others have said it is available on CL, you could also run a WTB ad there too. When i bought the GN the AC system had been redone, but still retained the R12. I bought up some on CL just in case I ever need any. I actually paid less for it than I do for 134 in the stores. My Syclone had been converted before I got it to 134, by the numbers it's about the same as the 12, but the 12 just has a different chill to me.
 
It is converted to 134 with a complete newer system (2010). But now the system does not work. Has not worked for the last owner either. I found about 10lbs of r12 for $25. Why I am so worried about the AC system????? Leather interior and live in Hawaii. This is why I am worried about the AC.
 
Think I may have a leak at the 134 adapter. Can I simply unscrew it and put a new one on. Remember last time I did one it had some kind of lock tight on the threads.
 
As stated earlier in the post.....car is already 134.

I used some UV dye. Used the whole can. Don't see it coming out anywhere. Hear a hiss coming from the accumulator area. Wonder if the adapter could be leaking? Only UV dye I saw was around the 134 low side adapter and and were it dripped on to the A arms.
 
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