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Guest Message by DevFuse

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AC retrofit to R134a

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32 replies to this topic

#1 Guest_c150L_*

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Posted 16 October 2002 - 06:35 PM

Can someone explain retrofitting the AC in my car to R134a?
Aprox cost, steps, who can do? If I can do myself, where to get supplies. Probably heard this before, never lookied into it.

#2 Guest_Wagon Wagon_*

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Posted 16 October 2002 - 07:19 PM

Expect to spend about $35. Just buy the "retrofit kit". Be sure that ALL of the old refrigerent and oil is out of the system. Then you just screw on the adaptors, attach the can, turn the AC on, and push the button on top until the cans are empty. Took me about 15 minutes and now the AC is ice cold.

#3 Guest_edrach_*

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Posted 16 October 2002 - 08:29 PM

How did you get the old oil out?

#4 Guest_Marck_*

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Posted 16 October 2002 - 08:38 PM

What are the advantages and disvantages of the R134a vs. the stock R12?

#5 Guest_Wagon Wagon_*

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Posted 16 October 2002 - 09:26 PM

The R134a is legal, that's the advantage. It's a LOT cheaper too. Production of R12 was banned in 1995, so any R12 that you'd buy (have to have a license to get it) is leftover stock. When I worked for an auto parts store we used to sell 30lb kegs of R12 for $1000. However if your R12 system still works, just leave it alone. If it's not broken, don't fix it.

To get the old refrigerant out- I just opened up my AC system and let it fly. Sssssshhhh- don't tell anyone though, it's illegal to do that. I'm not sure of the *proper* way to get rid of it- ask a shop.

#6 Guest_NoahDL88_*

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Posted 16 October 2002 - 09:53 PM

what year is your car, because unless it was made after 1992 it will have all r12 hoses and seals and these will leak r134a after a very short time, i don't know what the experience is with subarus but with other cars you won't have ac after a few months, besides its winter, ac is over rated

Noah DL 88 Wagon
D/R 3" lift

#7 Guest_musty24_*

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Posted 16 October 2002 - 10:16 PM

The retrofit kits usually come with all the replacement seals you'll need. The receiver/drier or accumulator (whichever yours has) should be changed also because the desiccant used in the R-12 systems is incompatible with R-134a. Make sure if you get a new one to specify that it's for use with R-134a. Also, after you get all the oil out of the system, use either ester or PAG oil. Ester oil is most recommended because it is compatible with the mineral oil used in R-12 systems. If there is a small amount of oil left in the system it will be okay, however with PAG oil, they will not mix. Ester oil will mix with PAG and mineral oil, but PAG and mineral oil will not mix. Make sure you don't overfill the system with oil.
If you replace any hoses, get barrier hoses. New hoses for R-12 will leak R-134a because the R-134a is a smaller molecule than the R-12. That's also why the seals should be changed. If the hoses are not in need of replacement and have been used for a long time with R-12, they will work fine for R-134a. The mineral oil has built up its own barrier that will not allow the new refrigerant to leak out. Also, some shops have recovery equipment to suck out the old R-12, which is much better then just "cracking a line and letting it go". Also, it's best to have the system evacuated before charging with R-134a to remove any moisture or air left in the system. Evacuating holds a 27 in.. Hg. vacuum on the system for a min. of 30 minutes. It's also a good way to see if your system leaks. I think I wrote enough. I hope this helps.

#8 Guest_c150L_*

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Posted 17 October 2002 - 11:20 AM

thanks all. Read kind of quick, did someone mention where to get supplies to do this retro?

#9 Guest_Hondasucks_*

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Posted 18 October 2002 - 12:22 AM

Auto parts stores carry the kits. The one I bought didn't include seals, and the valve fittings it included were the wrong ones, but they gave me another set that had the right fittings. Although AFTER I filled the system, I discovered that my TSV (expansion valve) was clogged so now I have to drain it, change the TSV and Drier, and recharge it :-( Prolly wait till AC class to do this ;-)

#10 Guest_McBrat_*

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Posted 18 October 2002 - 12:59 AM

how much of the system you replace will depend on how much you want to spend, and how long you will keep the car (or how old it is)

For my 82 wagon, I just picked up a retrofit kit at Advance Auto Parts. my system was already empty of the old gas because of a bad compressor. I put in a used compressor, and put one adapter fitting on. (low side). Kit did not contain the proper adapter for the high side, but you don't need it to charge.

I followed the directions and it took just 2 cans to get ice cold AC.

There weren't any AC shops in town that would even touch my car for the AC retrofit.....

#11 Guest_thealleyboy_*

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Posted 18 October 2002 - 07:08 AM

I always take mine to the shop for retrofits. The guys that do mine are great, and they don't charge an arm and a leg.

The reason I don't do it myself is because on a retrofit, the system really should be evacuated and cleaned out well, and you need specialized equipment to do this. Also, you dont want to fool around with the seals and adapters mentioned above more than once. A good shop will get it right the first time with no leaks.

Also, I should mention that there is a new refrigerent out that is totally compatible with the old r12 systems, and safe for the ozone. My guys mentioned it to me when I took my 93 Loyale in for a retrofit, so I thought I would try it out. Overall, I was a little disapointed. It doesn't seem cold enough, and it was also more expensive than r134. I'd like to try it again before condemning it though. It may just be a blower/venting problem on this particular vehicle.

good luck, John

#12 Guest_Mike W_*

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Posted 18 October 2002 - 08:12 AM

I understand it's a good idea to start with a clean system, replace the hoses, seals and receiver/drier... but a number of guys I work with have had excellent luck with the retrofit kit from Wal-Mart. All they did was follow the instructions. I haven't tried it myself yet, but the $35 cure sounds promising.

#13 Guest_RickOregon_*

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Posted 18 October 2002 - 09:18 AM

Hey Dale,

I concur with several others here, who've done the quick retrofit using the R134a kit from Walmart or elsewhere. Did our '86 GL 4x4 wagon a couple years ago, never had any leaks, and it has the coldest A/C of any of our cars -- usually puts out 36 - 38 F air at the center outlet, and that's on hot days -- simply amazing.

And as already mentioned, you don't really need the high-side fitting, so if your kit doesn't include it, don't sweat it. But *do* make sure you read instructions carefully and fill from the low side, only. If in doubt as to which side is the low side, get some qualified advice -- don't take a chance.

When you add the refrigerant, do it in small stages as you measure the temperature coming out of the dash outlet. Let the engine run for about five minutes between doses of refrigerant. Just add enough to get the temperature low (35 to 45 degrees F). Don't add too much. If you add too much, the temperature will start rising again.

I purged a bit of the refrigerant from the high pressure valve with the engine off, when I got too much in, but I had a thick glove on and was in a well-ventilated area. I also protected other engine parts by covering them with lots of towels.

That was my brute-force way to do the conversion, not as elegant as using gauges, but it worked for me. (I might have taken it in to a pro, but we live so far out in the country that it was just easier for me to do it myself.) Your mileage may vary... Later, Rick

#14 Guest_Mike W_*

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Posted 18 October 2002 - 12:13 PM

Another good topic for the Ultimate Repair Manual?

#15 Guest_RickOregon_*

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Posted 18 October 2002 - 12:34 PM

I forgot to mention -- one other symptom of overcharging the A/C with refrigerant is that your compressor will have to work harder, and your engine will lug down and maybe even die. Or, if the system is equipped with an overpressure switch, the compressor won't operate at all. Many systems have a low-pressure switch which disables the A/C compressor when there isn't a sufficient quantity of refrigerant. I don't recall if Subaru's have either of these switches? Anyone know? Later, Rick

#16 Guest_c150L_*

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Posted 18 October 2002 - 02:32 PM


kind of getting cool here now, but come spring, I will deffinately. Ditto on knowing what the high side is. Never made the misteak, but making the error could be very hazardous when the little can in you hand blows up!

Did some if this years ago when you could get ther12. Still have a kit or 2 in the shed. (No r12.) I even had made a makeshift vacuum system to evacuate the system prior to recharging. That's gone, but sure could remake.

Thanks all!

#17 Guest_Mike W_*

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Posted 18 October 2002 - 03:01 PM

Speaking of it getting colder outside, does running the A/C with the heat turned on help to defog windows faster? Seems like I read that somewhere but never tried it in my EA81 or EA82T cars.

#18 Guest_c150L_*

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Posted 18 October 2002 - 03:15 PM

I think most newer cars do that automatically. Part of the defrosting (defogging?) is moisture on the inside of the windshield. Thus, the dryer air helps that situation a whole bunch.

#19 Guest_RickOregon_*

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Posted 18 October 2002 - 03:55 PM

That's my understanding, as well. A/C runs with the defroster on. That's a good thing, too, because it periodically circulates refrigerant and pressurizes the system, keeping seals from drying out. Rick

#20 Guest_Bill Putney_*

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Posted 18 October 2002 - 08:14 PM

"...it periodically circulates refrigerant and pressurizes the system, keeping seals from drying out"

...and keeps the compressor bearings from brinelling from the constant vibration in the same spot while driving (years ago, when mfgrs. first started having the compressor run in defrost mode, the bearing brinelling was the main reason that I heard for them doing it).

#21 Guest_RickOregon_*

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Posted 18 October 2002 - 08:20 PM

Bill, glad you added your 2-cents worth. Everytime you do, I figure it's worth a dollar! 8-) I learned something, pal. Thanks, Rick

#22 Guest_sonik_*

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Posted 19 October 2002 - 12:16 AM

If you still want R12 I know that the EPA certification is easy to get. You can take the test online (no time limit, open book) and the cost is usually $20 or less. www.epatest.com is one of them. 12oz cans are $10-20 on ebay.

#23 Guest_HillbillyLes_*

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Posted 19 October 2002 - 05:21 PM

I've done a half dozen or so using the "Wal-Mart" or "Auto Zone" type retrofit kits. All without a hitch or leak. A couple soobs and a few "others". All were as cold if not colder than the R-12.

One thing I did find out about over pressurizing/filling a Justy...The dryer has a lead plug that if over filled, will blow to release pressure before damage occurs to the compressor or other parts. Only thing is, though, once the plug blows, ALL the pressure leaks out. I sold the car without replacing the dryer but the buyer epoxied the hole where the lead plug was and had it checked and refilled....works great!!


#24 Guest_kevinsUBARU_*

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Posted 19 October 2002 - 06:24 PM

I used one of the kits on a Dodge Raider. The low side was the only only adaptor that fit from Advance Auto Part. What sucked though, is that the thing that screwed onto the can was leaking all over the fricken place...I think we got more r134a on the engine and my hands than in the system...:lol:

Only thing though, if you do spring a leak, dont get the mist in your eyes because it burns like a bizzznach:) Also, if you get the R134A on your hands, it has a lot of oil in it, so its hard to clean off.


#25 Guest_musty24_*

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Posted 19 October 2002 - 07:06 PM

Make sure you don't breathe it either, it can cause sudden death.

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