Cooling Discuss all of the aspects of cooling that you can think of! Radiators, transmissions, electric fans, etc.

AC conversion

Old Jun 5, 2016 | 08:05 AM
  #1  
Wesley Hooper's Avatar
Thread Starter
Junior Member
iTrader: (1)
 
Joined: Mar 2013
Posts: 26
Likes: 0
From: Oregon
Car: 1988 Camaro
Engine: 305
Transmission: Auto
AC conversion

I am looking to convert my AC from R12 to the newer stuff. Is it worth taking it to a shop for all the work involved or do those retrofit kits work well? I'd prefer the cheaper option if it works well.

Last edited by Wesley Hooper; Jun 5, 2016 at 10:19 AM. Reason: Wrote to convert twice.
Reply
Old Jun 5, 2016 | 12:53 PM
  #2  
paulo57509's Avatar
Supreme Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2000
Posts: 3,178
Likes: 48
From: Tracy, CA
Car: '87 IROC
Engine: LB9
Transmission: TH700R4
Re: AC conversion

What "newer stuff" do you have in mind?

Some say that the cheap R12 to R134a conversion kits you get at the DIY places work fine.

Others feel that the only way to do a conversion properly is to disassemble and remove all the system components, flush out and clean the components to get out all traces of the incompatible oil (R12 and R134a use different formulations of oil), re-assemble with new components (as required), fill with the proper oil and re-charge.

I have seen TSB's from manufacturers (Honda for one - see attachment) that have conversion kits (still available ) that are similar to the DIY kits. I suppose this is an official approval that a kit is I have been told that you can run the system with both compatible and incompatible oil in it; the TSB seems to back this up. The incompatible oil is just a benign component that won't affect system performance.

The only R12 to R134a conversion I have done, I went the disassemble and flush route because the compressor had failed and I wanted to get all the debris out of the system.

The only time I would ever use a conversion kit is if the system is leak-free and running cold and I know that the compressor is not going to frag anytime soon. I guess by default I would never use a kit. If the system is leak-free and performing well, there is no reason to convert.

Edit: P.S. - Do not put anything in your system that has a sealer in it.
Attached Files
File Type: pdf
r12 to r134 conversion.pdf (563.3 KB, 674 views)

Last edited by paulo57509; Jun 5, 2016 at 12:56 PM. Reason: Added post script
Reply
Old Jun 5, 2016 | 02:18 PM
  #3  
Wesley Hooper's Avatar
Thread Starter
Junior Member
iTrader: (1)
 
Joined: Mar 2013
Posts: 26
Likes: 0
From: Oregon
Car: 1988 Camaro
Engine: 305
Transmission: Auto
Re: AC conversion

Originally Posted by paulo57509
What "newer stuff" do you have in mind?

Some say that the cheap R12 to R134a conversion kits you get at the DIY places work fine.

Others feel that the only way to do a conversion properly is to disassemble and remove all the system components, flush out and clean the components to get out all traces of the incompatible oil (R12 and R134a use different formulations of oil), re-assemble with new components (as required), fill with the proper oil and re-charge.

I have seen TSB's from manufacturers (Honda for one - see attachment) that have conversion kits (still available ) that are similar to the DIY kits. I suppose this is an official approval that a kit is I have been told that you can run the system with both compatible and incompatible oil in it; the TSB seems to back this up. The incompatible oil is just a benign component that won't affect system performance.

The only R12 to R134a conversion I have done, I went the disassemble and flush route because the compressor had failed and I wanted to get all the debris out of the system.

The only time I would ever use a conversion kit is if the system is leak-free and running cold and I know that the compressor is not going to frag anytime soon. I guess by default I would never use a kit. If the system is leak-free and performing well, there is no reason to convert.

Edit: P.S. - Do not put anything in your system that has a sealer in it.
I meant R134a I just couldn't remember the name lol I am leaning towards the disassemble route because I think it would be better. Is there a tangible difference R12 and R134a besides cost to recharge?
Reply
Old Jun 5, 2016 | 04:49 PM
  #4  
paulo57509's Avatar
Supreme Member
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2000
Posts: 3,178
Likes: 48
From: Tracy, CA
Car: '87 IROC
Engine: LB9
Transmission: TH700R4
Re: AC conversion

Originally Posted by Wesley Hooper
I meant R134a I just couldn't remember the name lol I am leaning towards the disassemble route because I think it would be better. Is there a tangible difference R12 and R134a besides cost to recharge?
Yes there is a difference. R134a doesn't cool as efficiently as R12. It's a function of the design of the AC system. 3rd Gen systems were not designed for R134a.

That doesn't mean R134a doesn't work. It works but not as well. There are things that you can/should do to improve it some what like installing a different orifice tube, changing the high pressure switch on the compressor, replacing the tube and fin condenser with a cross-flow, etc.

I strongly recommend browsing this forum before doing anything:

http://www.autoacforum.com/

Most of the good info is in the archived forum in the procedures, tips and faq section.
Reply
Old Jun 5, 2016 | 11:42 PM
  #5  
Reid Fleming's Avatar
Supreme Member
iTrader: (2)
 
Joined: Sep 2006
Posts: 2,118
Likes: 15
From: Houston, TX
Car: 1989 GTA
Engine: SuperRam 350
Transmission: Pro Built S/S TH700R4
Axle/Gears: 3.27
Re: AC conversion

I would remove the compressor from the engine and dribble some PAG oil into it while spinning it by hand to flush as much of the old Mineral oil out of the compressor it as possible.

Might as well replace the hoses (about $50) with new ones. The new ones will be barrier hoses and have zero mineral oil in them.

New accumulator with PAG poured into it before hand. The original system uses 6 oz of mineral oil. Put about 3 oz in (since some oil will still be in the evaporator and condenser.)

Any new "kit" will undoubtedly come with red and blue R-134a "push on" ports rather than the screw on ports that R-12 systems had. The new ports screw onto the old ones.

Might as well replace any O-rings that are in the system with new ones. Lube the new O-rings with Nylog blue. (Nylog is a mucus like product that makes O-rings retain their softness. It also helps with preventing leaks.) Use Nylog on any threaded connectors that need tightening too.

Vacuum the system and charge with R-134a.

Optional items: Swap out the GM white orifice tube for a Ford blue orifice tube. This will help with city driving and stop and go. Adjusting the low pressure cycle switch down a few psi helps too. See that rubber connector with the two prongs attached to the accumulator? Remove the rubber piece and in between the two prongs is a flat head screw. Turn that about 45 degrees to the left to lower the low psi cycle off point from 25 psi down to about 22 psi.
Reply
Old Jun 6, 2016 | 08:48 AM
  #6  
Queball's Avatar
Member
 
Joined: May 2015
Posts: 113
Likes: 0
From: Prescott Valley, Az
Car: 92 Camaro RS
Engine: 5.0
Transmission: 700r
Re: AC conversion

i had the money to do the complete change over, but before i made a choice i went to
my mechanic iv had for many years. he has been rebuilding camaros for years and owns a shop.

he straight up told me. "you will NOT like the r134 in this car" dont do it.

now if u live in an area where heat isnt high then r134 will feel nice to u.
if you live in hell heat states (arizona etc) then r12 is the way to stay COLD

so i replaced my compressor , had him fill it up fresh r12 an DAMN..in 110*F temps in good ol AZ..im ice cold in the car..my passengers tell me plz turn down the AC!! lol

but its your money..its your car..personally i say dont change over.
Reply
Old Jun 12, 2016 | 11:18 PM
  #7  
Buickstaged's Avatar
Member
iTrader: (1)
 
Joined: Dec 2014
Posts: 144
Likes: 1
From: Chisago city mn
Car: 1984 firebird se
Engine: 305
Transmission: 700r4
Axle/Gears: 373
Re: AC conversion

Reid, hoping you can help. I have an 84 bird that had belts. Converted to a serpent system from an 89 chev 2500. The ac compressor went from left(drivers side) to the right side. I hear talk of changing out the office tube, I cannot figure where it should install. Can you help me with location? Thx Byron
Reply
Old Jun 13, 2016 | 04:52 AM
  #8  
mikeceli's Avatar
Supreme Member
20 Year Member
iTrader: (2)
 
Joined: Jan 2005
Posts: 1,396
Likes: 199
From: S. UTAH
Car: 1989 IROC-Z 305 LB9 AT Convertible
Engine: LB9 305
Transmission: AT
Re: AC conversion

http://www.ebay.com/itm/R12-R-12-REF...hXPMZK&vxp=mtr


or check Craigs list and find an AC shop that will install it.

Your AC will operate best w/ the correct refrigerant.
Reply
Old Jun 13, 2016 | 12:13 PM
  #9  
3rdgenmaro's Avatar
Supreme Member
20 Year Member
iTrader: (9)
 
Joined: Dec 2004
Posts: 2,042
Likes: 18
From: Lincolnton, NC
Car: 88 IROC
Engine: 97 5.7 Vortec LT4 hotcam
Transmission: 700 r4
Axle/Gears: 3.73
Re: AC conversion

R-152a is a good alternative. Some information on this site about the swap. Might want to look into it. $12 for a charge vs $80ish for R12.
Reply
Old Jun 13, 2016 | 12:55 PM
  #10  
92RS-HeritageEd's Avatar
Senior Member
10 Year Member
iTrader: (2)
 
Joined: May 2015
Posts: 674
Likes: 23
From: Ohio
Car: 92 RS / 90 IROC-Z
Engine: 305 / 350
Transmission: Auto
Axle/Gears: Non-Posi / Posi - Both GU2 - 2.73
Re: AC conversion

I couldn't find anyone in my area with the tools or R-12...then I searched my local Craigslist on a whim... now I'm waiting on price quote!

Last edited by 92RS-HeritageEd; Jun 13, 2016 at 01:09 PM. Reason: UPDATED
Reply
Old Jun 16, 2016 | 10:44 PM
  #11  
Reid Fleming's Avatar
Supreme Member
iTrader: (2)
 
Joined: Sep 2006
Posts: 2,118
Likes: 15
From: Houston, TX
Car: 1989 GTA
Engine: SuperRam 350
Transmission: Pro Built S/S TH700R4
Axle/Gears: 3.27
Re: AC conversion

Originally Posted by Buickstaged
Reid, hoping you can help. I have an 84 bird that had belts. Converted to a serpent system from an 89 chev 2500. The ac compressor went from left(drivers side) to the right side. I hear talk of changing out the office tube, I cannot figure where it should install. Can you help me with location? Thx Byron
This isn't my picture. But it will do the job.



#2 is pointing at the high side schrader valve. Just after that, the metal line bends down. Right where it bends down, you can see the spot where you'll need to use a wrench to open that up. Actually, the picture has a zip tie right where you need to loosen that nut. Once you remove that, the orifice tube will be sitting in there straight up and down.

A pair of needle nose pliers helps to get it out. Pull and twist gently and it should come out. Pay attention to which way the old one was installed and replace with a new one.

Obviously, the system has to be free of refrigerant before opening up that line.
Reply
Old Jun 17, 2016 | 07:13 AM
  #12  
Buickstaged's Avatar
Member
iTrader: (1)
 
Joined: Dec 2014
Posts: 144
Likes: 1
From: Chisago city mn
Car: 1984 firebird se
Engine: 305
Transmission: 700r4
Axle/Gears: 373
Re: AC conversion

Reid, thank you for your response. It is very much appreciated. I don't think I ever considered that location. This again, regards, byron
Reply
Old Jun 24, 2016 | 11:36 AM
  #13  
Bob88GTA's Avatar
Supreme Member
20 Year Member
iTrader: (2)
 
Joined: Apr 2000
Posts: 3,938
Likes: 99
From: Huntsville AL
Car: 88GTA
Engine: 5.7TPI
Transmission: Auto
Axle/Gears: 3.27
Re: AC conversion

Originally Posted by Reid Fleming
I would remove the compressor from the engine and dribble some PAG oil into it while spinning it by hand to flush as much of the old Mineral oil out of the compressor it as possible.

Might as well replace the hoses (about $50) with new ones. The new ones will be barrier hoses and have zero mineral oil in them.

New accumulator with PAG poured into it before hand. The original system uses 6 oz of mineral oil. Put about 3 oz in (since some oil will still be in the evaporator and condenser.)

Any new "kit" will undoubtedly come with red and blue R-134a "push on" ports rather than the screw on ports that R-12 systems had. The new ports screw onto the old ones.

Might as well replace any O-rings that are in the system with new ones. Lube the new O-rings with Nylog blue. (Nylog is a mucus like product that makes O-rings retain their softness. It also helps with preventing leaks.) Use Nylog on any threaded connectors that need tightening too.

Vacuum the system and charge with R-134a.

Optional items: Swap out the GM white orifice tube for a Ford blue orifice tube. This will help with city driving and stop and go. Adjusting the low pressure cycle switch down a few psi helps too. See that rubber connector with the two prongs attached to the accumulator? Remove the rubber piece and in between the two prongs is a flat head screw. Turn that about 45 degrees to the left to lower the low psi cycle off point from 25 psi down to about 22 psi.
Thought I would jump in here instead of another thread.

Getting ready to charge tomorrow. I have new compressor,hoses, accumulator,and orifice tube. Evacuated system down to 28hg. It held all night. The new compressor came with the Freeze oil in it.
Question is..how much refrigerant will this system hold? And do I need to add any more oil?. I bought the 30# Cylinder of R134 and the scale.

Any help would be great!

-Bob
Reply
Old Jun 24, 2016 | 12:46 PM
  #14  
mikeceli's Avatar
Supreme Member
20 Year Member
iTrader: (2)
 
Joined: Jan 2005
Posts: 1,396
Likes: 199
From: S. UTAH
Car: 1989 IROC-Z 305 LB9 AT Convertible
Engine: LB9 305
Transmission: AT
Re: AC conversion

Your AC will work best w/ the R12 it was designed for.

$20 can below (not me).

Your car, your $$.

https://nashville.craigslist.org/pts/5606535944.html
Reply
Old Jun 24, 2016 | 01:00 PM
  #15  
Bob88GTA's Avatar
Supreme Member
20 Year Member
iTrader: (2)
 
Joined: Apr 2000
Posts: 3,938
Likes: 99
From: Huntsville AL
Car: 88GTA
Engine: 5.7TPI
Transmission: Auto
Axle/Gears: 3.27
Re: AC conversion

Thanks Mike
Reply
Old Jun 28, 2016 | 10:05 AM
  #16  
Mylilbowtie's Avatar
Junior Member
 
Joined: May 2003
Posts: 79
Likes: 1
From: Cincinnati area
Car: 1988 Iroc-Z / 1992 RS
Engine: 5.7 TPI / L03 TBI
Transmission: 700r-4 / 700r-4
Axle/Gears: 9 bolt 2.77 posi / 10 bolt 2.73
Re: AC conversion

Originally Posted by Reid Fleming
Swap out the GM white orifice tube for a Ford blue orifice tube. This will help with city driving and stop and go.
Any more information about this blue ford orifice / expansion valve? Year model ?
Reply
Old Jul 4, 2016 | 10:13 PM
  #17  
Pro's Avatar
Pro
Supreme Member
20 Year Member
 
Joined: Oct 2003
Posts: 1,083
Likes: 4
From: DFW
Car: 1992 Z28
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: G80 3.23
Re: AC conversion

Dont you have to have a license to service an R12 system, but R134a you can recharge yourself at home
Reply
Old Jul 25, 2016 | 02:15 PM
  #18  
Kaleel's Avatar
Junior Member
 
Joined: Nov 2013
Posts: 1
Likes: 0
Re: AC conversion

The stock compressor seized up on my '88 5.7 IROC. Getting a new compressor, accumulator, etc. The shop is installing the conversion kit from R12 to what I assume is R134. Figured I might as well get everything done at once. Shop quoted me $800. Obviously not thrilled about this but I'll let you all know how it works out after the job is complete.
Reply
Old Jul 26, 2016 | 08:15 PM
  #19  
Pro's Avatar
Pro
Supreme Member
20 Year Member
 
Joined: Oct 2003
Posts: 1,083
Likes: 4
From: DFW
Car: 1992 Z28
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: G80 3.23
Re: AC conversion

Originally Posted by Kaleel
The stock compressor seized up on my '88 5.7 IROC. Getting a new compressor, accumulator, etc. The shop is installing the conversion kit from R12 to what I assume is R134. Figured I might as well get everything done at once. Shop quoted me $800. Obviously not thrilled about this but I'll let you all know how it works out after the job is complete.
Mine was converted to 134a. Pics attached (part number of compressor)
Attached Thumbnails AC conversion-img_0540.jpg   AC conversion-img_0541.jpg  
Reply
Old Jul 31, 2016 | 11:19 AM
  #20  
84Z28dude's Avatar
Junior Member
iTrader: (2)
 
Joined: Jul 2016
Posts: 26
Likes: 0
From: Andover KS
Car: 84 Z28
Engine: 305
Transmission: auto
Re: AC conversion

Originally Posted by Bob88GTA
Thought I would jump in here instead of another thread.

Getting ready to charge tomorrow. I have new compressor,hoses, accumulator,and orifice tube. Evacuated system down to 28hg. It held all night. The new compressor came with the Freeze oil in it.
Question is..how much refrigerant will this system hold? And do I need to add any more oil?. I bought the 30# Cylinder of R134 and the scale.

Any help would be great!

-Bob
Seems like there is a label under the hood that should say how much, I think mine says 3 pounds.
Reply
Old Aug 1, 2016 | 07:31 AM
  #21  
Bob88GTA's Avatar
Supreme Member
20 Year Member
iTrader: (2)
 
Joined: Apr 2000
Posts: 3,938
Likes: 99
From: Huntsville AL
Car: 88GTA
Engine: 5.7TPI
Transmission: Auto
Axle/Gears: 3.27
Re: AC conversion

Originally Posted by 84Z28dude
Seems like there is a label under the hood that should say how much, I think mine says 3 pounds.
Yeah, Label said 2.85lbs I believe
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dixie wrecked
Interior Parts for Sale
12
Aug 8, 2016 05:33 PM
Carly_Nikole
Convertibles
2
Jun 20, 2016 06:54 PM
1Aauto
Sponsored Vendors
1
Jun 14, 2016 11:55 AM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 10:37 AM.