A/C R12 to R134

[Max Von]

I know. I shouldn't have but I did. After a few too hot interstate cruises, I decided to get the A/C working again in the '88 Carrera.I understand these automobiles were never designed to have fantastic air conditioning , and yes I too enjoy having the windows down and the sunroof open, but at 75 to whatever MPH it can get old real fast on a 90 degree plus sunny humid day when you have 2 or more hours ahead of you so please, gentle readers, spare me the "if you want great A/C, buy a Ford."
I've watching this BB and reading about the pro's and con's of changing over to R134. I talked to at least a half dozen dealers and independent shops and most times you mention R12 you get the same eye rolling, head shaking response. I was on vacation this week and happened to stop by a good friends very reputable shop. I explained my situation to the shop foreman and he took a look at the system. He advised that a very thorough evacuation followed by an R134 recharge, including changing the oil in the system, should have the car comfortable on most hot New England days. I've worked at several Jaguar and Volvo dealerships as a parts manager (I am still recovering and in therapy, thank you) and remember that most retro R134 kits include at least a receiver drier and the oil and o-rings. Jim assured me that they have done dozens of these conversions with no ill effects without chaning the drier.
Long and short of it, against my better judgement,(like a tattoo?) I gave the go ahead.
Two hours later......center vent temp on a 82 degree sunny low humidity (dew point 55) day,is steady at 42 degrees. Drove home cool and comfy.
On the highway at average commuter speeds on hot days the vent temperature never gets above 47 degrees.
I am pleased with the results, but feel I have taken a short cut and will have to pay the price down the line. I realize the later 911's don't have the barrier hoses etc. and I would have prefered to at least change our the receiver drier. Anybody else changed over to R134?
I would also be curious to see what other owners are getting for temperature readings from their A/C. I checked out my 1995 Saab Aero and it was at 49 Degrees constant.

Thanks,

Max

[vjd3]

I just had my 88 Carrera converted to 134 with a new receiver/dryer ... vent temp was in the low 40s, car is comfortable with temps near 90 in traffic on the #2 fan speed. It doesn't freeze your face off the way a Mercedes or Saab will, but the car is quite comfortable.

Vic
88 Carrera (for sale)

[CEO]

I am currently redoing my entire A/C system.
I have the C2 decklid on my 81 SC so the old condenser will not fit. So I put the C2 condenser in the front driver fender with the aux fan. Anyway I am changing to barrier hose a rotary compressor and a new reciver drier a new blower motor and new expansion valve.. I will let you know how it all comes out.

------------------
Kenneth
Silver 81' Targa

[Joeaksa]

Kenneth,

How much hassle is changing out all the hoses? How much did you pay for them and where? Am thinking of doing the same and curious...

TIA,

Joe

[Roland Kunz]

Hello

One problematic issue is the PAG oil. All factory recomidations stick to PAG witch can cause big trouble. On the other side Porsche uses "capped" PAG

Most "free" R134a conversions run with POE oils. Now if you hit the correct wights and did your other homework the system will work.

The dryer needs to be upgraded to newer XH types. However I know some companys who just flush with a "secret" reconitioner and then refill with 134a on mineral oil.

I´m not a air condition specialist and the funny thing is that on some people the thing will work despite the industrie says no while on other companys it will not work correct even used the factory recomedations

Just some links for more background info:


http://www.delanet.com/~pparish/gen-rp.htm

http://www.motorage.com/edindex/0103feat1.htm

http://www.aircondition.com/wwwboard/index.htm

Grüsse

[Joeaksa]

Max,

Just going back through some old A/C posts and found yours. One year later, how do you like the R134 and any problems with it so far?

Joe

[Max Von]

Hello Joe,

We had a couple of 90 degree plus days here in Boston a few weeks ago and I turned on the A/C only to discover it was blowing cool, but not cold. I had the system checked at the shop and the pressure on the low side was low, apparently in need of a charge. I had them evacuate and recharge the system and now performs well again, 42 degrees F at center vent at 3200 rpms on the highway although that was on a fairly cool (65 degree F) day.

I feel the best judge of A/C performance is any female passenger with fresh makeup on the way to a wedding. If it isn't cool enough, you're gonna here about it! No complaints last year on a couple of hot days.

I've read a lot of post on this subject and feel that if I could have found a shop that would deal with R12 in this region, I would have stayed with it. I plan on keeping this car and will look into possibly updating to barrier hoses and R12 later on down the road if the R134 doesn't pan out long term. The R134 seems to be doing the job for now anyway. We'll have to see how things go as the ambient and humidty rise. My major worry was that I have polluted the system with R134 and would not be able to switch back to R12 at all.
Just a side note. I have the service records for my car dating back to delivery in 1988 and the A/C system was recharged 3 times in all these years.

Max

[Joeaksa]

Thanks for the update and am even more convinced that the only way to go with any cooling medium is to replace the hoses to the newer style barrier hoses to keep the leaks down to a minimum.

Thanks,

Joe

[Max Von]

No sweat Joe (pardon the pun).

I am very interested in SeaDwellers system. Sounds like he's going to have to change his user name to "Cool hand (or knee's) Luke".

Max

[Joeaksa]

Agree 110% about Michaels system in Tampa. Cannot wait for him to return from vacation and fill us in on how his system works with the new hoses and such.

He is the one who is really testing the system with the heat and humidity there. I lived in Sarasota December and January and you needed A/C even then on some days. Phoenix was balmy compared to that place when you factor in the humidity.

Joe

[Sunroof]

Interesting.............
I had this going several weeks ago when I posted R12 Versus R134. Lots of great responses. For you guys who have the newer (not red cloth) hoses consider yourself lucky. My 73.5 T is loaded with them and thats my major problem on R134 conversion. From what I learned on this post the molecular size of R134 is smaller then R12 and therefore I will loose much in the old hoses. Its a small fortune to replace them all so for me the best I can do is deal with an R12 recharge and hope it keeps the sweat to a minimum!

One very interesting point for you R12 folks is that it is available in those nice cans as my mechanic showed me a fresh box direct from New Jersey. The key I guess is to get that license for R12
purchase and find that distributor!

Regards
Bob
73.5 T

[ChrisBennet]

I had my '86 converted to 134a 2-3 years ago and I think only the drier was changed. It's time to get it recharged again but it has performed adequately for New England summers. I used to have to get my R12 system recharged about as often.
-Chris

[911nut]

Originally posted by Max Von
"if you want great A/C, buy a Ford."

I concur!

[Max Von]

Touche'!

[Sean Hamilton]

Joe,
I agree. Looking back over the service records of mine, it's been re-gassed every year, (sometimes twice) with R134.
I cannot find any bugger to agree to fill her up with R12.
And now, after 6 months since I last R134'd it - and checked the complete system over with a trace for leaks - it's now cool, NOT cold.
PITA!!