DIY R12 to R134a conversion

[alia176]

I wanted to hear from the DIYers on this project. If you did your own R12 to R134a refrigerant conversion, what all did you end up replacing? I'd imagine you'd need to replace the dryer, replace the O rings, compressor oil and flush the system with a flushing solution. Are you changing the condenser as well to a larger one?

On the other hand, if I have a local A/C shop do the work, what kind of a price should I be expecting? The shop will need to evac the old stuff, remove the old oil, change the dryer and then recharge the system with R134a.

Does Subaru offer a conversion kit containing a dryer, O rings, etc.?


Thanks for any input.

Regards,

Ali
'92

[Rotorflyr]

Not specific to the SVX, but I have heard of people just putting the 134 into the 12 systems without changing anything, and having no problems (can't say as I would do it, just that I have heard of it being done)

[Earthworm]

I've heard of people doing that too but it's not proper. You should at least change the oil. I believe the R134 will leak out much faster without the proper o-rings.

[JIMSVX]

Ali - Here's several Endwrench articles on retrofitting the '92 SVX (and other Subaru models) from R12 to R134, including Subaru Kit part-numbers and instructions:
http://www.ravensblade-impreza.com/techdocs/pdf/vent/acretro.pdf
http://www.ravensblade-impreza.com/techdocs/pdf/vent/retro.pdf

This is an Endwrench article that discusses the R134 refrigerant in general:
http://www.ravensblade-impreza.com/techdocs/pdf/vent/134.pdf

Finally, here's an article on all the Subaru A/C systems that will probably tell you more than you ever wanted to know.
http://www.ravensblade-impreza.com/techdocs/pdf/vent/ac1.pdf

- Jim

[Chris]

A product called HOTSHOT is made as a non-cfc replacement for R12. I have talked to people who have used it without problems. I am going to use in on my recently purchased SVX once I get a tranny in it. Will report my findings then.

[comp_jas]

I bought the WalMart Interdynamics conversion kit.

Unfortunately to do it right you need a vacuum pump and gauges. Can you borrow some?

The pump allows you to pull a vacuum on the system. This will boil off any moisture in the system. Water boils at a much lower temp in a vacuum.

The gauges let you confirm that the system will hold the vacuum (no leaks).

I did not replace any hoses, o-rings etc. It still has adequate charge two years later.

You might get by w/o the pump and gauges. I opened the system to replace the condensor. Source of my lost R-122.

[JIMSVX]

Ali - Here's several Endwrench articles on retrofitting the '92 SVX (and other Subaru models) from R12 to R134, including Subaru Kit part-numbers and instructions:
http://www.ravensblade-impreza.com/techdocs/pdf/vent/acretro.pdf
http://www.ravensblade-impreza.com/techdocs/pdf/vent/retro.pdf

This is an Endwrench article that discusses the R134 refrigerant in general:
http://www.ravensblade-impreza.com/techdocs/pdf/vent/134.pdf

Finally, here's an article on all the Subaru A/C systems that will probably tell you more than you ever wanted to know.
http://www.ravensblade-impreza.com/techdocs/pdf/vent/ac1.pdf

- Jim
I meant to add that I had the conversion done by our local mechanic (who has done the conversion on other non-Subaru models.) He replaces the dryer and oil but no O-ring change. The cost was $230 and so far it's still putting out nice, cool air (he said with his fingers crossed.)
- Jim

[alia176]

Thanks fellas for the ideas. I'll review the endwrench article to get a flavor of what's up ahead. Chances are I may simply have it done by a pro but I like to know what is involved. I'm about to embark on replacing all seals up front so if the motivation is still there I might just start the conversion. But, I do need to have it evacuated by a shop to keep it environmental friendly. :D

I'll look into the conversion kit (92 svx kit p/n G31110PS000) cost and see if it's worth the effort. After evacuation, I can pretty much do everything except pulling a vacuum. I suppose I can rent a vacuum pump but we'll see!

Ali

[Conn SVX]

After not being able to hold a charge I took my SVX to a dealer he suggested trying the conversion, I alread spent $100 on the hard to get expensive R12 and the charge was lasting a week. The dealer changed all the valves and recharged it , that was 4 years ago for $150.00 I just used it last Sat and it still puts out cool air. ( not as cool as the original #311 I could have made jello on the front pass seat with that one. ) Still cold enough.

[alia176]

I went to Subaruparts.com for prices to come up with some numbers for the "kit" that the Endwrench article mentions.

KIt G3110PS000
Receiver/drier - $106
Suction hose - $152
Discharge hose - $152
O rings, PAG oil, R134a retrofit label - neglible
----------------------------------------------
Total cost approx $410 :eek:

Being a cheap bastard that I am, I'll just purchase the Drier and see what the local A/C shop wants to gouge me for! :cool:

[benebob]

I put R134a into my 6 last spring with just changing the low pressure side (the high wouldn't fit right and leaked so I left it off) valve. Nothing else as I didn't have a clue if it even worked to begin with and didn't wanna spend the time. Worked just fine. Did have to add about a 1/4 can this year. Definately not as cool as the SVX set up with my 95 but much better than before.

[Conn SVX]

I am going to check with my Subaru Dealer and ask what they did to mine. Hey you could call them and ask. Center Subaru Torrington, Conn. Tell them Mr Lucky the guy with the White SVX , told you to ask. Ask for Service. I know I didn't pay any $300.00

[alia176]

I called my local dealer to see how badly they can rape me. They don't have the retro kit in stock so I told him that I'll supply all parts. All they have to do is perform labor. This is going to be good ;)

Ali

[kuoh]

I just did this on my 92 and only replaced the drier and the two associated O-rings. The drier was only about $35 from Advanced Auto and came with the O-rings. The retro kit was an Interdymanics with a pressure gauge and 3 cans of R134+Oil. The 92's only had 21-25oz of R12 to start with, so you only need to fill it with 17-20oz of R134. At first, I didn't bother with evacuating the system and it seemed to work, but was somewhat intermittent. The next day, I took it to a shop and paid them $70 to evacuate the system, then refilled with the left over cans of R134 from the kit. It seemed to be more effective, but I didn't get a chance to really test it out since I had to go on a trip shortly after. All told, I only spent $150 or so and will be happy even if it only lasts another couple of years.

Kuoh

[s'ko]

bump from the cellar

I was wondering how people's systems are holding up.

I have to get the AC recharged in my wife's 92SVX and i was considering going with a r134a conversion. estimate to recharge right now is 50 bucks labor and $90.00 per pound of freon.

Thanks

BW

[Tuck]

I did this two weeks ago and so far, so good. I got a pressurizied can of flush, a filter/dryer, a blister pack of o-rings, two cans of R134a and a bottle of PAG oil to do the job from AutoZone. I already had a vacuum pump. I removed the compresser and drained the oil before replacing it with the PAG oil. Then I flushed the system, replaced the o-rings, and filter/dryer. Pulled a vacuum on the system and after seeing there were no big leaks, charged the system and was ready to go. BTW one of the cans of R134a had a leak stop in it and the other had a leak dection dye.

Why do I have a vacuum pump handy? I live in Florida and every time I took a car to get the A/C repaired it was $600. :mad: The pump was $400 @ Grainger.

Tuck

[SVX_MY_BABY]

Had mine converted in Dec 1999. Still cools great.

Replaced the dryer & o-ring. Only did the dryer because of the new refrigerant, nothing wrong with it.
Dryer No. 73031PA000, O-ring No. 73039AA060

Cost about 300.00 to diagnose loss of charge and do the conversion. If it's going to set you back 150.00 knowing you have a leak and there is a very good chance the Freon will leak again (which is environmentally bad) why bother? Just do the conversion.

[immortal_suby]

Did mine last summer with an advance auto retrofit kit - no o-rings changed or drier or anything other than the fitting which was included. Still on the original compressor at 239k. I just evacuated the system and dumped in the new stuff. Still cooling great so far this year and it is HOT down here!

[YourConfused]

I have no a/c and sighted my comp to condenser line due to the build up on it as the culprit. I am curious about how many people needed new compressors when the a/c went out. Over the last 10 yrs I hardly ever worked on a subaru, so I have no personal history with them like a honda, lexus, gm, or bmr. Looks like the system is super easy to work on so I am just wondering about common fail items so I can check their availability and prices. It's heating up in texas and it is time for the a/c to get a kickin.

[dcarrb]

Entering my fourth summer with the teal SVX running R134a; all I recall the mechanic replacing was the filter/dryer (aside from the condensor-to-compressor hose, which was weeping when I bought the car). The system cools just fine and has required no re-charge nor other attention.

dcb

[thumper_svx]

I almost hate to say it because then I KNOW I'll have problems, but with three SVX's, one Loyale and one Outback in the last 11 years, I've had exactly zero compressor failures. The Loyale was converted to R134 from R12 as well... and the Outback was R134 to begin with. Subaru compressors seem very well engineered and built (all of these 5 Subarus got over 150K except my current SVX which is at 137).

Now, that's not to say I haven't had problems with my other cars. I've replaced a compressor in a Chrysler Town & Country (twice) (122K when it was totaled), and a 96 Saab 900 Turbo (130K when sold, and the compressor was getting noisy again). Having said that, I had a Ford Escort I converted from R12 to R134 that was at 186K miles when I sold it and the AC still worked like a champ. Needed recharged about twice a year because the system wasn't very well sealed... but it worked well and never once did I have to replace the compressor.

Take from this what you will... just my observations :) BTW, when I replaced compressors they had completely seized in the Chrysler, and "burst" (Saab).

[davew833]

I used to drive mid-to-late '80s Hondas and I replaced a TON of compressors on those, mostly Nippondenso, some Hitachi. (Not sure who makes them for Subaru.) Seemed I could never keep a Honda system working! My advice on retrofits would be to avoid the so-called 'death kits' from AutoZone and Wal-Mart which promise conversion from R12 without doing anything but adding R-134a and oil. They WILL work for a while, but usually at the expense of killing your compressor. Also, most shops will not work on your A/C system if they know you've done a DIY conversion without purging and evacuating your system first. It's really important to get all of the old stuff before putting anything new in.

[Earthworm]

For those who don't already know there are about 13 o-rings in the entire A/C system. The most likely ones to fail are the ones on the top of the compresser.

Mine worked great ever since I converted to r134 by replacing all the o-rings, compresser oil and dryer unit.

Getting the system vacuumed is and the proper amount of r134 (professionally) installed is recommended.

[SSSVX]

My advice on retrofits would be to avoid the so-called 'death kits' from AutoZone and Wal-Mart which promise conversion from R12 without doing anything but adding R-134a and oil. They WILL work for a while, but usually at the expense of killing your compressor.

Why would they kill your compressor? If you use the kit, but do it with the right way by vacuming out the old stuff and put in the oil and R134a in?

[SSSVX]

Glad to know most Subarus' compressors are reliable. But the one on my yellow one was out/seized at around 142K. But the one on my Teal one(still R12, low-low mileage) worked beautifully and never needs recharge yet for 6, 7 years.

Dave, do you think any difference for compressors compare as Group 1(92 and 93) and Group 2(94 to 97)? Just wonder do they change the compressor to work with R134a freon better after 94? Just thinking maybe the compressors on 92 and 93 work less efficiently after converted to R134a?

[immortal_suby]

update:
my AC blows so cold I have to turn the temp up to avoid freezing my hands. Drove to the beach this past weekend with the outside air temp gauge reading 100 and the AC was still super strong.

Still no problems with the DIY cheapo R12 to R134 conversion canister from advance auto and stock (240k miles) o rings.

[alia176]

So far, I've replaced the drier, all O rings, Evaporator (came with expansion valve), rebuilt compressor and I can't remember what else. I think I have a leak somewhere on the compressor somewhere. At least, that's what the A/C shop tells me anyway.

When I pull a vacuum in the system, will this really pull the oil out of the system as well? I thought this might only pull the old R12 and some oil. Technically, I should remove the comp and drain the oil the old fashion way. Let me know if this sounds right. I'll be using a Robinaire vacuum pump for creating vacuum.

As far determining how many cans of R134 to dump into the system, I'm guessing that I should have the hi/low press gauge set to tell me. However, since I'm suppose to dump in more R134 than R12, due to lower BTU, I'm trying to figure out what psi should I aim for on the hi/low press gauges.

Thanks.

[immortal_suby]

Well, I guess 4 years ain't too bad. Leaking AC system now from the connection on top of the compressor.

I hope my universal O-ring kit is made of the one of the accepted materials, or it's time to order new rings.

[torxxx]

I've had mine self converted for almost a year now and it still works fine. all I did was purge the system, put a vacumn on it for 20 minutes to get all the oil out of the system and then injected new 134a oil and was good to go. finding fittings was the hardest part for me. the retrofit kit didnt have the right fittings

[92 SVX]

I was told that draining all the R-12 oil would be counter productive, sure some will come out when you vac the system but its helpful to have some in the system it will coat the o-rings and keep the R-134 from eating them.
You just need to vac the system and add the PAG oil then the R-134.

My system was converted some point before I bought the car, they have a sticker on the rad support, I assume it was leaking as they indicated they put dye in the system
It has never worked that well I have had several problems with it I dont think they replaced any parts they just put the screw on adapters for fitings. Found that my low side port fitting was leaking so after recharging I took that fitting off appears to have held for 6 months now.