Thanks for everybody's advice. Had her charged up today and all is well. Nice and cool on this 95F day. First time with AC since I bought her. Hopefully she'll hold the charge.

 

Keep us updated. I am looking to repair my a/c soon too.

 

this type of thread always gives a bunch of directions to go in and i get confused all over again.

i'm going to be doing all of my seals and dryer soon and want to know what refrigerant to use. not just what will "work", but what is best replacement for r12. it's been years since r135a has come out and now there seem to be possibly "better" alternatives for our old r12 system cars. i don't want to have to replace a bunch of parts unnecessarily. guys who use other refrigerants don't tend to give updates later on how their systems are doing. i was leaning toward the dust off until i read on how flammable it can be. then i read on m-39 being a more direct replacement, etc….lost all over again.

i just want to know what's best. maybe i'll go ask a refrigerant shop.

 

134a is best, easy to retrofit, inexpensive, plentiful, works great, at least in a gen 1 944. It has been 110 here in Tucson and 134a keeps up just fine. I have been getting 29 degree vent temps at cut off, kicks back on about 45 degrees. Some cars do very poorly with a 134a conversion, depends on the system.

 

1. Go on Griffiths site--why ask a shade tree mechanic about AC info? Griffiths knows the Porsche.
www.Griffiths.com

2.Some freon alternatives are flammable. The 25-30 YO hoses in the car were not designed for some types. Additionally, the OEM R12 hoses will leak Freon and should be replaced ---eventually. Do you plan to replace all the seals under the dash?

3 To get comparable temps-replace the condenser with a dual core.

4 A new or rebuilt "Denso" compressor built for R134a will work the best.

J_AZ

 

Meh. R152A (computer duster spray) in my 968 R12 system is great, otherwise all stock. Mineral oil, stock condenser, stock compressor, stock hoses. Replaced the drier for $15. R134A works OK in systems designed for it. I am totally uninterested in it as a conversion gas.

's chilly.
-Joel.

 

All refrigerants are mixed with oil and are extremely flammable if the system were punctured. FYI, R152a is classified as low flammability, not high, not that it matters when mixed with oil. There is just not that much of the refrigerants to be a major concern. You may also read that r152a produces a poison gas when burned, but so do r134a & r12. I did quite a bit of research and have seen nothing to indicate it is any less safe than r12 or r134a and is cheaper and better for the environment than both.

I will be doing the r152a change very soon and will provide feedback.

 

So assuming you have to replace the hoses, do you have to drop the engine to do so?

 

I have replaced all the hoses on 2 of my cars with engine in place. If you can find a beadlock crimping tool you can make them look just like factory.

 

did you replace with OEM hoses or did you cut an crimp onto existing lines?

 

The hardest two hoses to do are the high pressure line that goes to the receiver/drier and the low pressure line going to the compressor. The reason these are harder is the hard lines are attached to the car. The compressor to condenser and the condenser to receiver dryer are easy because you can remove the whole line.

The hardest part of doing the job is using a dremel and removing the existing beadlocks. You have to cut the beadlocks off without damaging the metal line below the hose. I wish I had one so you could see. If you are careful you will not have a problem. You don't cut the existing metal line only the beadlocks.

Here is a picture of the hardline to hose on my 968. I used Gates AC barrier hose.

 

Ok, why not follow the official Porsche technical service bulletin for the conversion, guess Porsche and us shade tree guys are idiots!!

 

What seals under the dash are you talking about

 

On the late 944's you have two o-rings under the dash where the expansion valve is. I would not worry with them. If you go to R134 (which is what I did on my 968) then you should do the following as far as hoses and 0-rings. Put in new 2 new o-rings at the receiver/drier. 2 new o-rings at the compressor and 2 new o-rings at the condenser. I would make or buy from griffiths a new high pressure barrier hose going from the compressor to the condenser.

 

So, no need to switch out the oil in the compressor with Ester Oil? Should I remove the compressor and change the oil anyway?