Silvertarga

You cant just throw R134 in an R12 system, received/dryer has to be changed and of course the seals (and valve) get changed as well

You can go to the local auto parts store and buy the R134 top ups buit they wont do you a bit of good if your 964 havent been changed over

My local A/c guy is keeping me on R12 as long as he can...he is not fond of the R134 in my PCar and so far so good..

bmohr

I really appreciate the feedback guys. I will try to recondition the seals, check out and possibly source a new reostat(any part numbers for this?) first. Silver, when you say you just can't top off the new refrigerant onto of the old stuff is this because of a chemical reaction?

Edit: i think i'm reading your post correct now Silver - the old R-12 system has different valves that won't fit with the new coolant refill tanks. Is that it? Sorry, my first porche was a 99 c4 and didn't have these hvac issues But since my c2 is a daily driver I really could use the ac for defogging the windows. I really do appeciate all the advice and feedback!

Silvertarga

The two refrigerants are not compatible (thats why the different valves)

With the system empty so long it is best to have it flushed out...old oil residue and other contaminants may be present

bmohr

found German Auto Parts sells the R-134 conversion kit for 20 bucks, drier for 25 bucks and a resistor for 50 bucks. I'm assuming the rheostat switch you were talking about is the resistor? Part number:

993 616 521 01 - Series Resistor for Oil Cooler and A/C Condensor Blower Fans

user 783003

Just bought the conversion kit and the drier. Skipped the resistor for now. My clutch won't engage automatically. If I put 12 volts to it, it engages. I also couldn't get it to take a charge.

Hopefully I'll be closer to having a working air conditioner with these parts and a conversion to 134.

Laker

be aware that the resistor sits underneath the acid blow-off hose from the battery, so it is setup for failure.

Makmov

And the bolt wont come out or it will break off.

but you kind of need a working one if you expect the AC to work

user 783003

With the new drier and conversion kit on order, I'm looking for a procedure. Looked at Wachuko's DIY, but it looks like he was doing more than I want to tackle. Anyone know of a DIY to convert to R134? Aside from the resistor mentioned above and the two pieces I've ordered, any other parts or materiels needed?

-nick

Hi Alfred,
It's a fairly simple conversion.

1. Have a shop evacuate all the R12.

2. Replace the receiver/drier under the driver-side front wheel well. Easy: remove plastic well-liner and the drier will be right in front of you. Replace the black o-rings for the AC-line connections with green (from your kit).

3. (optional) unbolt the AC compressor and tip it over to let any oil inside drain out the AC line ports. My understanding is that excess oil will decrease the cooling ability and every little bit helps.
3b. Replace the black compressor AC-line o-rings with green.

4. Screw in the new R134a ports onto the compressor. *If your new ports have a valve core then you'll have to have the valve cores in the compressor pulled out. AC shop should have the tool to do this and it just takes a second.

5. Have a shop pull a vacuum on the system, then fill with oil and R134a according to spec. There is a thread somewhere that shows a page from the factory manual on the hi/lo pressures and ambient vs. vent temp. I think our AC runs on lower pressure than most cars so make sure the shop knows 911's.

Good luck. I've never been satisfied with my AC. Now that my driver side blower fan is squeaking, I'm going to replace it and upgrade the evaporator core with Griffiths version while it's all out. Not looking forward to it...

user 783003

I don't believe there is any r12 in there. I brought it to a local indy shop and their recommended hvac shop a year ago to see if they could charge it. They said they tried to put a vacuum on it to see if there was a leak and they said they couldn't get a vacuum on it. Not that it wouldn't hold a vacuum, just that they couldn't get one on it. Doesn't make sense to me.

Aside from the r12 risks to the environment and it being illegal to release it, what are the risks to me and/or the car if there is any and it gets released? Again, based on the fact that they don't think there's anything in it...

altarchsa

If they couldn't pull a vacuum, it means the leak was too large for the vacuum pump to even generate a reading on the gauge. If you can get a vacuum but can't hold it, it means the leak is small.

You don't want to let the freon leak under pressure onto your skin or it will freeze it. Don't get it in your eyes or breathe it, obviously. Other than that, it's just Big Brother.

altarchsa

BTW, there's a new rheostat on eBay right now. Don't know how the price compares to Vertex etc.

user 783003

With shipping, the ebay one is $70. The one on germanautoparts.com was $55 or so without shipping and they didn't specify shipping costs, you just order and hope they're not high (the shipping costs).

No affiliation with either place (ebay seller or german).

altarchsa

I thought I had seen them for about $35 on eBay. Try Vertex (no affiliation).

Earlydays

Griffiths sells a kit for the 964 that is $129 with a receiver/dryer.
http://www.griffiths.com/shop/index....02e32f06fbd187