A/C conversion R12 to 134a help
#1
A/C conversion R12 to 134a help
Hey guys, I have an a/c question. It's getting hot and I would like to get it working again in my 1990 4runner. I wanted to convert it to 134a. I bought the adapters and made sure all of the r12 was out of it. What else do I need to do? I bought the 134a already but I wanted to make sure it was going to work before I go wasting my money. Any help would be greatly appreciated.
#5
I just completed this on mine. I took all the hoses off and cleaned and replaced all the o-rings. Remove and empty the oil from the compressor. Clean out the evaporator and condensor with denatured alcohol and blow everything out with compressed air. Replace the receiver-dryer. Reassemble,add ester oil and vacuum down and check for leaks.Recharge with R-134 and enjoy! I'm getting 42* at the vent by doing it this way. It took a good day to do this.
Last edited by thralldad; 07-11-2010 at 07:13 PM.
#6
Damn, I was hoping I could just put the 134a in and it would work. Will it still work if I choose not to clean it out? All of the r12 is out now. Also does the oil need to be changed or can I get away with letting it in?
#7
Registered User
thralldad is right, you should clean out the system and find out what caused it to stop working in the first place (if it failed under the use of R-12). At least put a vacuum on it to make sure there are no leaks, and if there are none, use a refridgerant with a seal conditioner & compressor oil. I wasted 2 cans of 134 on my brother's Civic because I didn't know the compressor seal had gone bad. As for the compressor oil - not sure about that. I think the oil recirculates with the refridgerant... I'm prob wrong about that though.
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#8
Registered User
If you use Freeze 12 you don't need to clean out the compressor or anything, and it has very similar characteristics to R12.
I was going to convert mine, but then I decided otherwise. The R12 cools much better, and i need everything I can get in my big 4runner cab. Plus i read that R-134 puts a bigger load on the motor because it's hard to compress, and I can't afford to put much more load on my motor so I'm sticking with R12. You can get it on ebay, and then take it to a "qualified" person to put it in, or if you want to risk it just put it in yourself.
I was going to convert mine, but then I decided otherwise. The R12 cools much better, and i need everything I can get in my big 4runner cab. Plus i read that R-134 puts a bigger load on the motor because it's hard to compress, and I can't afford to put much more load on my motor so I'm sticking with R12. You can get it on ebay, and then take it to a "qualified" person to put it in, or if you want to risk it just put it in yourself.
#9
Ester is compatible with R-12 and 134. Pag will cause your oil to gel and smoke your compressor. Your leak is most likely an o-ring and the originals are black and the R-134 ones are green. The originals are probably hard and brittle by now,therefore leaking. It's some work but that COLD air is super nice in the Texas heat!
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DJames (08-16-2022)
#12
Registered User
Hi guys, i've been reading that the condensor needs to be replace when converting to r134a, and that the accumulator can be flushed instead of replacing it. I've already flushed the hoses and evaporator, and added new o-rings from a retrofit kit i bought. So is it the condensor or accumulator that needs to be replaced? Was planing to flush the accumulator tommorrow.
#14
Registered User
i payed $32 for the retrofit kit(all a/c o-rings, ester 1oo, and new ports with caps).
$17 for 12oz of a/c flush, so about $49 dollars while learning how to fix/maintain my a/c system as i service it. I'm kinda the cheap one in the family, but still work for quality. Plus the shops around here charge around $80, unless i drive all the way to el centro.
$17 for 12oz of a/c flush, so about $49 dollars while learning how to fix/maintain my a/c system as i service it. I'm kinda the cheap one in the family, but still work for quality. Plus the shops around here charge around $80, unless i drive all the way to el centro.
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dmw310 (06-23-2020)
#17
Registered User
a simple search just showed me a few for yours online , '84-'89 are all the same from $90-$210 recommend denso since they'll be the closest measurements and the fact some of Toyota parts are made by them that they out source. Unless your fine with used ones for $15-$40.
#18
You really should go get vacuumed down and filled correctly. I can almost guarantee you there is moisture trapped in your system. That will corrode and cause failures. Also filling from the low side is fine, but the issue is that you have no idea what the high side pressures look like. There is a volume difference between r-12 and r-134, and the high side pressure will show you when the system is up to the correct pressure. You cannot put the same amount of r134 in as you had r12..