dondeziner

Is anyone aware of any articles on the proper procedure to convert R12 to 134a in a 964? If anyone could advise me of what is the right way of doing it I would greatly appreciate it.

Thanks.

Don
90 C2

964porschedude

There is a Porsche Service Bulletin on the conversion. I have all but sheet 8 in pdf file format. I see If I can't get the missing sheet from the dealer and package it up for you. When I purchased my 964, the whole-sale lot converted it to R134a before I picked the car up. Apparantly the system was low and they opted to do a short-cut conversion. I have collected all the parts to do the conversion as directed in the SB, but the system still runs well and is pretty cold. I plan to change out the o-rings and flush the system with the cleaner, then pumping it down for an extra bit of time to get as much water out as possible. I will change the dryer, o-rings, oil, and fill 85% of original charge.

As far as the rubber hoses, they say that the oil from the original service from Porsche, fills the pores in the hose and the new freon (R134a) can't get through. The dryer uses a different filter media that is better than the R-12 dryer and matches the R134a compound. You will need ot change the Fill fittings.

Roygarth

The current issue of 911&PW has a large artice on Airconditioning!

Brgds
Piers

BaysideC4

I filled mine with Freeze 12 (R12 substitute) and it's now blowing ice-cold air. It's completely compatible with R12 systems but only cost $9 US per can. I highly recommend it! It also operates at a much lower pressure than R12. I bought an entire conversion kit for under $50 US.

A neighbor of mine works for a bus company as a mechanic and they fill all the busses that run low on R12 with this stuff. It works great and is a direct replacement. No compressor oil change and no receiver dryer change needed.

It is definitely something to consider if you have a small leak. Its ozone safe and if you need two cans per summer its no big deal. I have not needed a refill yet and I have had it in for months. Even blows ice cold when it’s 95 degrees outside.

Just my .02 =)

dondeziner

Thanks for all of the help. Look forward to getting the Service Bulletin and will pick up the latest issue.
Thanks again.

Don
90 C2

Jerry Garwick

Hey, Bayside

What did the conversion kit consist of, if the stuff is compatable with R12? Could I just top my system off with it without the conversion kit?

BaysideC4

Jerry,

You need the kit because the fitting is a different size (I guess you can tap the can with an R12 hose, never thought of that). When doing this all your R12 will escape. The kit was like $41 plus shipping. I think it came with three cans. I only used one and part of another.

Jerry Garwick

Bayside

The current issue of Excellence advertises a product called Duracool 12a (Supposed compatible with R12) Do you know if it's the same stuff? They didn't mention a conversation kit.

Where did you get a line on the "Freeze 12?"

BaysideC4

I read about it here:
http://autorefrigerants.com/freeze12faq.htm


I bought it here:
http://www.sherco-auto.com/

There are a few kits, I got this one:
*No affiliation

A note about applying the new fitting - It screws on over the old fitting. I used Plummer’s tape to seal the threads. You must unscrew and remove the inner pin on the old fitting as the new Fitting has it's own pin.

Hope this is useful information to you. This stuff is great!

springer3

It has been a while since I researched this topic, but I recall there is an EPA web site on R12 alternatives that is authoritative. The problem with all the "drop in" replacements is that they are a mixture of two or more refrigerants. They work fine, but you cannot tolerate leaks as some have suggested. The problem it that one of the refrigerants in the mix will have a smaller molecule, and will leak out faster than the others. If you leak any significant amount, your mix will drift over time to a higher concentration of the heavier refrigerants. Your performance will suffer, but I don't know if it will be bad enough to notice.

Jerry Garwick

I went down to the local Fresno, CA auto suppliers and was told that , as of last week, they cannot sell FREEZE 12 or similar products to anyone without a hvac California license. They can sell the R 134a products, however, over the counter. I love this state (of confusion.)

964porschedude

Try buying it off the web. http://freeze-12.com/

Randall G.

Hey Jerry,

I'm surprised that they told you "as of last week." When I was looking at Freeze-12 last year, the case was the same = you had to have a license. This applies to any of the R-134a (or should I say R-12) alternatives. I tried to call (no answer, voice mail never returned) and e-mail Freeze-12, asking if they had an authorized installer in my area. No response.

I finally gave up and converted my car to R-134a. In retrospect, a good move, as the stuff works well, and is cheap and readily available.

Jerry Garwick

Randall

About what should I expect the cost of converting to R-134a to be? Should I go to a Porsche shop or can any reputable A/C shop do it?

Randall G.

Hey Jerry,

I think you can have the conversion performed by a non-Porsche specific, reputable, A/C shop. That's what I did--the dealer wanted a lot more than an independent shop. It helps to point out where components are in oddball locations--e.g., the condenser and drier/receiver. It also helps to bring a copy of the page from the Porsche manual, showing how much R-134a to charge by weight.

My conversion cost $264.83. $59.71 including shipping for a new drier/receiver from Vertex, which I supplied to the A/C shop (you don't want the factory item....around $200). Labor was $130. $20 for two fittings, $10 for oil, $36 for R-134.

It's surprising how many shops don't think R-134a will work well in our cars. When I called around about having my car converted, about half the shops (including at least 1 dealer) tried to discourage me from doing it. On the other hand, it's my understanding that our systems were designed for 134a, in anticipation of R-134a being mandated (R-134a was installed in 964s in '93). Thus, it being so simple to convert. Perhaps they're thinking of earlier 911s? Or, general experience with other cars? Dunno'.