R12 to R134A?

wolfen1086 · 09-27-2009, 09:27 AM

I've heard that if I want to convert a 89 S-10 Blazer A/C system from R12 to R134A all I have to do is pump the 134 in without changing anything over, is this true?
Or am I better off with the windows open?

**Raylo** · 09-27-2009, 09:40 AM

I wouldn't recommend this. At a minimum you need to thoroughly flush the system and install a new LP cycling switch. The r12 and r134a oils are not compatible with each other and the cycling pressures are different. Also, r134a is a smaller molecule and you should get low permeability compressor high and low side lines. Probably not absolutey necessary but advised. You may also need to change the compressor as those older ones might have seals that won't work well with 134a. I'm not sure about this, tho.

wolfen1086 · 09-27-2009, 11:50 AM

I've heard that from several people, teh one who told me to just "dump it in" is supposed to be a mechanic at a local dealer, but since I've had this Blazer I have found that I do my own work at a much higher quality than any dealer around here.
Thanks, I think I'll just stick with teh open window system and add another sliding window in the rear.

09-27-2009, 09:27 AM	#1 (permalink)
wolfen1086 Registered User Join Date: Oct 2007 Location: Va Beach Posts: 248 OS: Win XP SP3	R12 to R134A? I've heard that if I want to convert a 89 S-10 Blazer A/C system from R12 to R134A all I have to do is pump the 134 in without changing anything over, is this true? Or am I better off with the windows open? __________________ I'm gonna rot ? yea I know, might as well smile in the mean time :)

09-27-2009, 09:40 AM	#2 (permalink)
Raylo TSF Enthusiast Join Date: Feb 2006 Location: Maryland, USA Posts: 525 OS: XP Desktop, Vista HP Notebook, XP Notebook	Re: R12 to R134A? I wouldn't recommend this. At a minimum you need to thoroughly flush the system and install a new LP cycling switch. The r12 and r134a oils are not compatible with each other and the cycling pressures are different. Also, r134a is a smaller molecule and you should get low permeability compressor high and low side lines. Probably not absolutey necessary but advised. You may also need to change the compressor as those older ones might have seals that won't work well with 134a. I'm not sure about this, tho.

09-27-2009, 11:50 AM	#3 (permalink)
wolfen1086 Registered User Join Date: Oct 2007 Location: Va Beach Posts: 248 OS: Win XP SP3	Re: R12 to R134A? I've heard that from several people, teh one who told me to just "dump it in" is supposed to be a mechanic at a local dealer, but since I've had this Blazer I have found that I do my own work at a much higher quality than any dealer around here. Thanks, I think I'll just stick with teh open window system and add another sliding window in the rear. __________________ I'm gonna rot ? yea I know, might as well smile in the mean time :)