Hey all,

I just converted my A/C to 134a the quick way. My shark has recently become my daily driver, and it is starting to get hot in the Kansas City area (I only have one functional window at this time as well). I decided that desperate times call for desperate measures. I was planning on replacing the receiver/drier, compressor, seals, and doing an evac/recharge, but I needed cold air now. I bought a conversion kit that is supposed to be compatible with R12 and installed it. Essentially you remove any R12 (mine had none), install the high and low pressure conversion fittings, and recharge the system. So far it is working pretty well. The conversion fitting for the low side briefly leaked, and may need to be replaced, but the system is now blowing cold with 134a. My thought process was that I couldn't damage anything that I wasn't already planning to replace. I'l update to let everyone how it works out.

 

R134a, while not as bad as R12 on the stratospheric ozone, is still a green house gas.

Since you didn't bother to fix the leaks, your polluting the environment more than the other cars on the road.

borland
90' S4, Slate Metallic

 

You are assuming that my system will leak more than the average car of its age. You don't know that, and I don't either yet. All A/C systems leak over time. The act of driving a vehicle, that burns fossil fuels, emits "green house" gasses. I would have to sit down and do some calculations, but I would bet that driving a car on long commutes for a week emits more ozone harming gasses than evacuating an entire automotive system of R134a into the atmosphere. How much do you drive your car each day? I put less than 30 minutes on my car a day. You may be putting a larger volume of offensive gasses into the atmosphere than the leaks that I "didn't bother to fix" will.

 

Borland give the guy a break .... Dude how many cars with ac have leaked it all out over the past 40 years ..... and are stilldoing it. No stopping that. At least he is using something a bit friendlier. Btw I was unaware that 134a was an Ozone killer?

 

So, did you vacuum down the system? I know you can blow cold and all that w/o doing an evacuation, but water vapor in the system will do damage to critical parts over time. I didn't think R134a was compatible with the oil used in R12 systems. How does this conversion work longterm without replacing the drier or evacuating the system? Was this perhaps one of the Freeze12 type kits which uses propane or another gas that is R12 compatible and not a real conversion to R134a? Curious minds want to know.

 

Thanks Heinrich,

For borlands benefit, and that of the world, I will try to limit the release of any offensive gasses .

 

Bill,

My understanding was the same yours before I tried this, and this could backfire in a colossal fashion. I didn't evacuate the system, and just added the 134a with what is supposed to be compatible oil. This is my first conversion of this type. In the past, I have replaced the compressor, orifice tube, evaporator, seals, and replaced the refrigerant with 134a or freeze12. The system had a very slight amount of pressure left when I started. It was not measurable on a gauge, but made a half second hiss when I pressed on the shrader valve. It was probably due to the car being hot after driving. I’m hoping that this means that I didn’t have any moisture in the system.

I started this thread relay my experiences with a possibly less expensive and alternative repair method of an R12 A/C system. I hope it works.

 

It will work for a time, but less due to the fact you didn't flush the R-12 (mineral) oil out of the compressor and install R-134 (Easte) oil.

R-134 has a hard time flowing R-12 oil through the system.

It beats riding around in a hot, hot car

Just be ready to do hoses, compressor, o-rings, drier, expansion valve(s) and some AC system flush. Right before you here the compressor go, it will have already contaminated your system with rubber and steel grindings/shavings.

A/C Rebuild, Jag style

 

Snoz,

You can get to everything forward of the evaporator fairly easily... at least on a 78. I think the S4+ cars with rear air have one hose that requires that you have the car on a lift and either cut the steel line and have a flexible section grafted in by an AC shop or pull the motor. Even the rear evaporator and expansion valve are fairly easy to get to. But getting that front evaporator out is some serious "Journey to the Center of the Earth" action. You basically start at the center console and disassemble everything up to the firewall to get that front evaporator out. I don't recall if the dash has to come out too, but either way it's a pretty big job. Thousands if you have a shop do it.

The thought of pumping hydrochloric acid through my evaporator makes me cringe.... but that's just me. Best of luck with your adventure!

Heinrich, it's all bad for the ozone. R134 is just not as bad as R12. So far as we know, anyway. Now that everything has switched to R134 , we have a decade or so of leaking it out into the atmosphere and soon enough there will be another study, another change... at some point it may just get ridiculous enough that it becomes worthwhile to run propane AC refrigerant and a halotron(or the next idea) auto-fire-suppression system. So it goes.

 

"I started this thread relay my experiences with a possibly less expensive and alternative repair method of an R12 A/C system. I hope it works."

Understood, but we attempt to discuss (and recommend to people) the proper procedures and solutions to 928 problems, I would not consider what you have done as a "proper fix", but it's your car and risk. I appreciate your post because it allows discussion on all options and surely, you are not the first to "drop a few cans of R134 in". I would ask people to consider all options before taking the attractive "less expensive" method, tempting as it may seem.

Seems less expensive today, BUT, there is a long-term price to pay. Incompaible oils are the root of this problem. It's not the "new" (probably Ester)oil which may be compatible with R12 (Ester is, PAG is not), it's the residual mineral oil residing in your system which creates a problem. Even though you had little or no pressure, mineral oil was present in your system. Do a web search for AC "Black Death"

Without new barrier hoses, your system will not likely hold the R134 for any great amount of time. R134 will find it's way out through the R12 perforated hoses.

BTW, charge R134 at 80% of the car's R12 capacity. If your system calls for 36 oz, of R12 as an example, charge 29 oz. of R134

What your car really needs for a long-term AC solution is- system flush, new expansion valve, drier, barrier hoses, O-rings, LP switch, compressor. Griffith's conversion kit is good system if set up properly. Do a forum archive search for detalis. or go here http://www.griffiths.com/porsche/index.html

I see a couple of options-

1) your new R134 may leak out in a couple of weeks, in that case, I would address a proper conversion.

2) your system holds the R134 until fall. At that point, time to do a proper conversion. Griffith's kit.

3) you keep pumping r134 into the system all summer, your system cycles on and off frequently because your R12 low pressure switch is set higher than a R134 LP switch (not adjustable) and the compressor will engage / disengage frequently. Just a waste of time and frustrating.

4) Your ssytem fails and you end up adding a "fun" evaporator replacement to your list of parts at proper conversion time'

Please let us know how this all turns, out, hope you stay coll all summer,
Greg

 

Heinrich.

R-134 is not a ozone killer. Note how he said Greenhouse gas. A Greenhouse gas can be as simple as CO2 all it does is absorb and hold heat very well, and does not like to shed the heat easily. It works like a blanket. Older ozone killers like CFC's actually become quite volatile at higher elevations where ozone works its majic agains U.V. light. One CFC molecule can destroy 10,000 ozone molecules.

Realize that R12 and R22 are still used in majority of the under developed world and are vented freely! I still prefer R12 to about anything out there. CO2 will likely be the next major refrigerant step forward, but the operating pressures of 4000psi offer some engineering concerns and challenges.

You will generate both HCl acid and very small amounts of HF acid in your a.c. after exposed time. Even if you don't, the water in your system will certainly cause rusting and damage.

It is Ester oil that is compatible with the R134a and R12. Better yet on a new setup is double end capped PAG oil. Flows with the refrigerant the best of all the oils and provides a robust difficult to cleave lubricant.

Good luck.

 

Snoz
So for the short term your car is blowing cold air....it will be interesting to see how long this fix lasts...hopefully till the end of summer!

Without vaccuuming down the system and changing the drier...I would assume there is quite a bit of water vapor in your system...& some of the older R12 driers are not compatible with the new 134. I have been told (by a local shop) that the "right" way to convert to 134 consists of removing the compressor and cleaning out all old R12 & oil, replacing all "o" rings, replacing both expansion valves (if you have rear A/C), replacing the drier and refilling with R134 (assuming your compressor works fine)...it also came with a quote for over $1100!!!

Keep us posted on how long it holds up!
Brian

 

The only thing I could find in the archives is from 2001:
https://rennlist.com/forums/928-forum/42402-griffiths-a-c-compressor.html
It quotes the price for the kit at $699. Anyone know if that's still the price? Any long term feedback from the kit?

 

Emit all you want. Then take a break and we'll get together for some barbequed spotted owl and a couple of brewskies.

As for A/C, all my R12 has leaked out and is in the shop as we speak being repaired by someone much more knowledgable than me. I like cold air!

 

Others have beaten you up and enlightened you, but you did use the terms "should" and "I hope" "is supposed to", so methinks you knew you were getting a quick fix and eventually you will pay more than if you had done it right the first time. It's all in the archives here.

We've already had brown outs in the sections of NYC and today is only the second day of summer. Others can joke about global warming -- it is real, and people who know say it will take 30 years to JUST TO APPLY THE BRAKES! which we have not done. The real problem with r12 is that one molecule grabs some huge number of O2 molecules and takes many many years to break down. Living in denial is self destructive.