Kit for switching from R12 to R134? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ggtsvnv · 07-31-2009, 08:17 PM

Hi,
I tried a search and didn't find what I was looking for. I have a question about switching the A/C in my 87 1/2 ton short bed to R134 from R12. I have read all kinds of different information such as "it's simple just change the oil" and recharge with R134 too "you have to replace all the "o" rings and seals to handle R134. What I was hopeing to find is a kit that has any or all seals o-rings or anthing else that needs replaced. So all I have to do is clean the old out, switch anything the needs replaced and recharge the system. Does anyone have a suggestions on such a kit or what needs to be done. I want to do it once and have it done for the next 10 years or so.
Thanks in advance

Restrorob · 07-31-2009, 08:38 PM

If you want the system to last look at this post; http://67-72chevytrucks.com/vboard/s...96&postcount=3

I myself don't know of any replace it all "Kits" but who knows.....

Good Luck

Malo83 · 08-01-2009, 03:29 AM

See if this helps

http://www.autoacforum.com/

SSC's76 · 08-01-2009, 11:00 AM

Follow resto robs information in his link this will be your best bet for a good conversion thats lasts. The R12 is gone so that means there is a leak in the system. Replacing the o-rings will help prevent a new leak. Im not a big beleiver in R-134a spec o-rings holding up any better then standard o-rings but you can get a r-134 O ring kit at any parts store. Its $20 for a master kit that come with more O-rings then you will ever use but its well worth it. Here is another link with some information you might find usefull. http://www.id-usa.com/how_to_faqs_retrofitting.asp

ggtsvnv · 08-01-2009, 01:08 PM

Thanks everyone lots of good info there

bumslie75 · 08-01-2009, 01:13 PM

I say dont do it. The air will never be as cold, what you can do is this stuff called freeze 12 its a synthetic r12 i put it in my truck this summer and on the day it was 113 here i was happy as a poler bear

hessian18 · 08-01-2009, 02:24 PM

I lucked out and found a buddy who had some R12 laying around, I went through and replaced my filter basket or "orfice tube" and I also replaced the o-rings at the pump. So far its been about 4 months and no problems here in the good ole hot desert. I havent checked it with the gauges lately.....Im sure it has bled off a small amount, since I had to replace a valve stem shortly after the fill up.

Other then that R12 kicks ass !!

mcbassin · 08-01-2009, 07:43 PM

If you do a search on Ebay there is tons of R-12 on there. I'm not sure, but I think your "supposed" to have a license to buy it.

jd74c-10 · 08-02-2009, 12:58 AM

go to walmart and buy a 134 retro kit for 35 bucks , vaccum the system and refill to specs. i have been doing it that way for years with no problems at all .if your system is good and clean the temp. will be just as cold as r-12.

Pyrotechnic · 08-02-2009, 01:25 AM

To do this right, I would recommend getting a new dryer/accumulator unit and orifice tube and a new o-ring set. Flush out your condenser and evaporator with alcohol to remove the old oil and contaminates. Flush the compressor with the new R134A compatible oil.

One trick to make R134A conversions work well is to step down a size in orifice tube. Instead of the stock GM white tube, use a Ford blue tube.

Desert1957 · 08-03-2009, 07:30 AM

Quote:

Originally Posted by Pyrotechnic

To do this right, I would recommend getting a new dryer/accumulator unit and orifice tube and a new o-ring set. Flush out your condenser and evaporator with alcohol to remove the old oil and contaminates. Flush the compressor with the new R134A compatible oil.

One trick to make R134A conversions work well is to step down a size in orifice tube. Instead of the stock GM white tube, use a Ford blue tube.

Please tell me more about this smaller orifice tube theory?
I understand how this orifice tube system works , is it just with the refrigerant more controlled to the evaporator it will be colder? Do tell...

Thanks Desert

Pyrotechnic · 08-03-2009, 11:03 AM

This is a huge topic for debate. I'm no AC tech so I'm just spewing back what I've read. It seems that everyone has their opinion on this.

R134A is a smaller molecule, and when converting to R134A you also only charge to system to ~80% of the original R12 charge. The smaller tube helps bring the high and low side pressures to what the system originally had with R12. It also helps the phase change from liquid to vapor as the refrigerant enters the evaporator.

http://www.autoacforum.com/ is a good place to read discussions on this.

gchemist · 08-03-2009, 07:34 PM

Install a secondary air condensor! The R12 condensor is a little small for R134.

07-31-2009, 08:17 PM	#1
ggtsvnv Registered User Join Date: Apr 2003 Location: Cold Springs NV Posts: 85	Kit for switching from R12 to R134? Hi, I tried a search and didn't find what I was looking for. I have a question about switching the A/C in my 87 1/2 ton short bed to R134 from R12. I have read all kinds of different information such as "it's simple just change the oil" and recharge with R134 too "you have to replace all the "o" rings and seals to handle R134. What I was hopeing to find is a kit that has any or all seals o-rings or anthing else that needs replaced. So all I have to do is clean the old out, switch anything the needs replaced and recharge the system. Does anyone have a suggestions on such a kit or what needs to be done. I want to do it once and have it done for the next 10 years or so. Thanks in advance

07-31-2009, 08:38 PM	#2
Restrorob The One And Only !!! Join Date: Jan 2007 Location: Hole in the woods Florida Posts: 4,567	Re: Kit for switching from R12 to R134? If you want the system to last look at this post; http://67-72chevytrucks.com/vboard/s...96&postcount=3 I myself don't know of any replace it all "Kits" but who knows..... Good Luck __________________ 93 Jeep XJ 88 Buick La Sabra Toys; 88 TA-GTA in the works.... 97 GMC Ext. Cab 502 Crate 5 Spd......Sucks Gas But Haulz Azz ! The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic. *"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!*

08-01-2009, 03:29 AM	#3
Malo83 Cruzzzn' Vet Join Date: Jan 2005 Location: Porterville,Ca. Posts: 1,918	Re: Kit for switching from R12 to R134? See if this helps http://www.autoacforum.com/

08-01-2009, 11:00 AM	#4
SSC's76 No No Join Date: Jun 2005 Location: Pueblo Colorado Posts: 1,781	Re: Kit for switching from R12 to R134? Follow resto robs information in his link this will be your best bet for a good conversion thats lasts. The R12 is gone so that means there is a leak in the system. Replacing the o-rings will help prevent a new leak. Im not a big beleiver in R-134a spec o-rings holding up any better then standard o-rings but you can get a r-134 O ring kit at any parts store. Its $20 for a master kit that come with more O-rings then you will ever use but its well worth it. Here is another link with some information you might find usefull. http://www.id-usa.com/how_to_faqs_retrofitting.asp __________________ 1976 Custom Deluxe SWB Med FMB.3/4 Drop. Gen VI 454, Muncie HD 3 speed With Modified OE Hurst Shifter, 3.73 12 bolt, GMPP HO roller cam, Hooker headers, Performer intake with modified Q-jet, Accel distributor. Best 1/4 12.3 @108. Funnest run 19.84 @88 full 1/4 mile burn out. 1997 K1500 ext cab 5.7 stock except muffler

08-01-2009, 01:08 PM	#5
ggtsvnv Registered User Join Date: Apr 2003 Location: Cold Springs NV Posts: 85	Re: Kit for switching from R12 to R134? Thanks everyone lots of good info there

08-01-2009, 01:13 PM	#6
bumslie75 Registered User Join Date: Apr 2009 Location: Reedley Ca Posts: 360	Re: Kit for switching from R12 to R134? I say dont do it. The air will never be as cold, what you can do is this stuff called freeze 12 its a synthetic r12 i put it in my truck this summer and on the day it was 113 here i was happy as a poler bear __________________ "There he goes. One of God's own prototypes. A high-powered mutant of some kind never even considered for mass production. Too weird to live, and too rare to die."

08-01-2009, 02:24 PM	#7
hessian18 Gen III Power Join Date: Sep 2007 Location: Hesperia CA Posts: 318	Re: Kit for switching from R12 to R134? I lucked out and found a buddy who had some R12 laying around, I went through and replaced my filter basket or "orfice tube" and I also replaced the o-rings at the pump. So far its been about 4 months and no problems here in the good ole hot desert. I havent checked it with the gauges lately.....Im sure it has bled off a small amount, since I had to replace a valve stem shortly after the fill up. Other then that R12 kicks ass !! __________________ ---Bob--- '81 Long Box. 2005 5.3l Vortec and 2005 4L80e coming soon...

08-01-2009, 07:43 PM	#8
mcbassin Still Learning Join Date: Jul 2009 Location: Central Oklahoma Posts: 10,108	Re: Kit for switching from R12 to R134? If you do a search on Ebay there is tons of R-12 on there. I'm not sure, but I think your "supposed" to have a license to buy it. __________________ Mike "69 Short Wide" My Project 86 Silverado Landen's Project Instagram: @mcbassin My Website C/10 Club Oklahoma Facebook Group

08-02-2009, 12:58 AM	#9
jd74c-10 Registered User Join Date: Jul 2009 Location: bullhead city az. Posts: 51	Re: Kit for switching from R12 to R134? go to walmart and buy a 134 retro kit for 35 bucks , vaccum the system and refill to specs. i have been doing it that way for years with no problems at all .if your system is good and clean the temp. will be just as cold as r-12.

08-02-2009, 01:25 AM	#10
Pyrotechnic Registered User Join Date: Feb 2007 Location: Austin, TX Posts: 3,930	Re: Kit for switching from R12 to R134? To do this right, I would recommend getting a new dryer/accumulator unit and orifice tube and a new o-ring set. Flush out your condenser and evaporator with alcohol to remove the old oil and contaminates. Flush the compressor with the new R134A compatible oil. One trick to make R134A conversions work well is to step down a size in orifice tube. Instead of the stock GM white tube, use a Ford blue tube. __________________ 1977 GMC Sierra Grande Last edited by Pyrotechnic; 08-02-2009 at 01:26 AM.

08-03-2009, 11:03 AM	#12
Pyrotechnic Registered User Join Date: Feb 2007 Location: Austin, TX Posts: 3,930	Re: Kit for switching from R12 to R134? This is a huge topic for debate. I'm no AC tech so I'm just spewing back what I've read. It seems that everyone has their opinion on this. R134A is a smaller molecule, and when converting to R134A you also only charge to system to ~80% of the original R12 charge. The smaller tube helps bring the high and low side pressures to what the system originally had with R12. It also helps the phase change from liquid to vapor as the refrigerant enters the evaporator. http://www.autoacforum.com/ is a good place to read discussions on this. __________________ 1977 GMC Sierra Grande Last edited by Pyrotechnic; 08-03-2009 at 07:01 PM.

08-03-2009, 07:34 PM	#13
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Re: Kit for switching from R12 to R134? Install a secondary air condensor! The R12 condensor is a little small for R134. __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos



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