Went to get my ac charged and was told I need an upgrade to get it to run on current freeon. Never had to charge an ac before and just got the car this week. 1988 NA 944. Anyone do this, and any advice on a kit. Where to get it how much? Thanks!!!

 

Some shops are licensed to fill using R12 (the old stuff) or a suitable replacement. Otherwise, you'll have to change over to R134 (the new stuff). The change-over is not cheap (to do correctly) and R134 arguably doesn't work as well, but it does make trees smile or something.

 

i would have a shop fill it with r12

 

you can do the "changeover" yourself overnight...

one afternoon, remove the AC compressor from the car. let it sit upsidedown in a pan to drain the oil out. flush it with new PAG/R134 oil, then put a few oz of fresh PAG/R134 oil in it. reconnect it to the car.

while the compressor is out and draining, replace all the o-rings in the system with the new green R-134 specific type. this is pretty easy. put some of the PAG oil on the rings before you install them to make sure they seat and dont dry out.

buy a new receiver-dryer ($11) and install it in place of the old one. you also need to put the R134 conversion fittings on your car, they screw on to the R12 fittings.

once the compressor is in, o-rings are new, and dryer is in, draw a vacuum on the system and see if it holds 25 inches of vacuum or more for a few hours. if it doesn't change over 4 or 5 hours you're probably leak-free. with the vacuum in the system still, hook up a R134 can and the vacuum will suck it out of the can. this should be enough to allow the compressor to run once you start the car.

with the car running and ac on full, charge the system to about 75-80% of the R12 spec (early car takes 40oz of R12, so 30-32oz of R134. late cars take less).

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...or save yourself a few hours and just refill with R-12 for like $100.

 

No argument that this method works, but I've personally had about a 50-50% rate of complete failure of the pumps shortly after doing this. The other thing is that the R12 lines will leak the R134 notably more quickly than they do R12, as the R12 molecule is much larger than the R134's, so you'll probably have to refill your system rather frequently.

I would definitely agree that spending $100 to have the R12 recharged is definitely the best way to go.

 

I know there is a place or two in KC that charge R12. There's no where close to Springfield that does it.

 

Rebuilding the compressor takes about 2 hours and about $20 worth of parts if you like

 

Can you even buy R12 over the counter anymore, or does a shop have to do it?

 

I'm in FL running R134a and it sucks compared to R12. Thing is the system was not designed to use R134a so there is a compromise in any conversion. My BMW e46 325ci is ice cold running R134a, so my question to a/c experts is:
Money no object, what would be required to upgrade the 944 to R134a?
Better condensor?
Better compressor?
Barrier hoses?
Better evaporator?
Is anything on the 944 system good for R134a?

 

got a link to where I can buy the parts? my compressor is leaking out of the metal casing, would be nice if I could rebuild it myself.

 

http://www.acsource.com/nippondenso_2.aspx

 

nice.. thanks!

 

I need to do something like this as well. I bought dozens of R12 cans which, when filling, cool things down real well for about 5 minutes and then regular air, no AC.

 

V2Rocket_aka944 posted the front compressor oil seal kit.

This is the usual place for a compressor leak.

If you want to do a full compresser seal rebuild here is a kit from Griffiths

http://www.griffiths.com/shop/index....roducts_id=190

Griffiths has an AC help page and technical info on R134a
http://www.griffiths.com/achelp/

If you feel you do not want to rebuild the compressor--V2Rocket can rebuild your compressor for a modest fee.

Locally in Phoenix R12 is $79 a pound. My 924Ss take 33oz. to fill and shop fees.

I have converted the '87 two years ago and it works great on R134a. R134a does take a little longer to cool down but I get 32 degree vent temps.

Walmart sells R134a for about $10 a can. Buy a case because R134a is being discontinued in a couple of years just like R12. The new freon introduced in Europe this year for the 2012 model year is Dupont Opteon and it is reported to sell for $30 to $60 a can and cannot be mixed/used with R12 or R134a.

http://www2.dupont.com/Refrigerants/...toAC/faqs.html

Rennlist sponsor 944online has a complete conversion kit with a new compressor. Most 944 conversion problems are caused by the old Nippondenso compressor.

http://www.944online.com/cgi-bin/ASI...skukey_1000962

TexasBlake has a great DIY
http://www.texasblake.com/porsche/tech/ac.html

Got it?
John

 

Thanks guys. I put up a post a while back asking if people had information about rebuilding the A/C compressor and I never got any responses. Now I know.