a/c questions

thamlin000 · thamlin000's Garage

I took my 83 944 into the shop today for a/c work after getting sick of sweating bullets in the humid 95 degree East Texas weather.

My a/c has been blowing hot air and the shop told me that my evaporator to compressor hose is leaking and must be replaced. The shop claims they might be able to fabricate their own hose, which would save me money. Tweeks sells these hoses for $299. I can't find prices from any other vendor.

Of course my a/c will have to be recharged. My a/c was last recharged with R12 back in 1999. I was told it had a leak but I choose not to have it fixed and it held charge for 3 years.

I know this is going to be very a $labor$ intensive job.

Questions:
1. Should I replace the condensor to evaporator hose with fabricated unit?
2. Should I recharge with R12 or R134a?
3. What do you think this will cost me considering all the work will be done by the shop?

Thanks for any input.

Paul Stewart · 05:59 PM

Don't be afraid to allow them to make the hose, I had one made for about $25 bucks a few years ago, it still looks new.

Converting to R134a will allow you to add refirgerant the next its low for a few bucks a can.

divezic · divezic's Garage

My opinion...

Convert to R134 just because it is cheaper to recharge (DIY) and it is theoretically safer for the environment. Problem is that R134 reportedly does not work well with our AC system. Talking to the guys at Zims (in TX), 100 deg ambient temps produce 70 deg AC air with the R134. In Brunswick ME that is not a problem, in Texas it might be a problem.

What little experience I have with auto A/C and with what I've read about our OEM compressors, I would seriously suggest change the compressor to a Sanden or Kuehl if you do go to 134. The higher operating pressure for the 134 will blow the seals on the OEM compressor.

According to the Tech Directive from Porsche, if you do the 134 conversion, the only components that must be replaced are the charging ports, o-rings and receiver/dryer. I am going to replace the expansion valve ($30) so I can do a thorough flush on my system.

If you get them to make you a new hose, make sure it is guaranteed. $200 labor twice for installing a $25 hose twice is not worth it.

Dave

kenny · 06-21-2002, 05:18 AM

I'm out here in Ft. Worth. My 951 has been converted over to R134a but I hear the earlier (pre 85.5) cars didn't have the same capacity. So far, it has been working pretty well but it isn't as hot here as it is going to get!

Lawrence Coppari · 06-21-2002, 05:56 AM

You might consider alternate refrigerants such as Duracool. Check this out www.duracool.com. I've used it for 6 years in one car and for 4 years in another.

thamlin000 · thamlin000's Garage

Thanks for all the suggestions. 134a with a guaranteed hose will be my course of action.

I'll keep you all updated about the repair.

kenny · 06-21-2002, 08:47 AM

OK just so we can get an I told you so going here, I would take Lawrence's suggestion. To really get the AC to work right with R134a the system would need some serious ($) modifications. I believe that the newer cars can get away with the swap because of the additional capacity, but from everything I've heard the earlier systems just aren't up to it. There are several R-12 replacements that are cost effective and more efficient (which you need) than the R134a -- you've been warned!

thamlin000 · thamlin000's Garage

I've been warned and now I'm worried.

I'm not going to rule out upgrading the compressor.

Is there any early 944 owners out there who converted to R134a without upgrading their compressor? Is there a noticeable difference in the a/c cooling.....especially those living in hotter climates.

kenny · 06-21-2002, 11:34 AM

Just out of morbid curiosity, what is the adversion to going with a R-12 substitute -- I think you still have to convert the fittings over to R134a, but I don't think that this is an expensive proposition, and the efficiency is much higher. The folks at the website Lawrence gave you said that their replacement was even more efficient than regular r-12.

Even though mine is working OK (note I'm also in TX), I was thinking of going back to the R-12 substitute myself for increased cooling and I already have a late model car. As you know! in TX it's all about staying cool in the summer!!! I'm interested to see how well my R134a conversion works down here in the 'heat of the battle'.

thamlin000 · thamlin000's Garage

The shop my car is at is pushing the R134a. I didn't see any prices for the R12 substitute and I also wonder about the cost/time of ordering it from Canada.

I'll do some more research.

**correction** I see I can order duracool from tenn.

divezic · divezic's Garage

Anybody know where we can buy alternative refrigerants like Duracool?

Paul Stewart · 06-21-2002, 07:23 PM

http://www.duracoolusa.com/

http://www.autocool-refrigerants.com/

AFJuvat · 06-21-2002, 08:46 PM

Converted my system to R-134A last week. - Charged it completely and have had no problems whatsoever.

Vent temps now running in the 40 - 45 degree range.

AFJuvat

Lawrence Coppari · 06-22-2002, 03:04 AM

Fox Tool Company in Nashville, TN sells the Duracool. It's about 6 bucks per 6 ounces. You use about 1/2 as much. I usually buy a case at a time for $72.

divezic · divezic's Garage

Thanks. I'm going to try it out.

muso58 · 06-25-2002, 03:53 AM

Does anyone have a contact for diy gas in europe pref Spain or UK Thanks in advance Steve Eliott

maachan · 06-27-2002, 09:34 PM

Hi,

I was following this post in the past with an interest. I have hot A/C on my car. I read the Duracool thing and was ready to order the stuffs. Just I was about to order, I thought I should ask a few questions to a mechanic who operates helicopter shop next door. He has all the equipments to do A/C work on cars to airplanes to helicopters.
He was not too hot about the Duracool. He says it is not readly available around here. Also it requires some modification to the system, he says.
So is he saying the truth? I would like to know. I would like to hear from someone who is using Duracool.

Maachan

kenny · 09:16 AM

see Lawrence's post above, 4 years in one car and 6 in another. I think all you do is change out (or get adapters for) the fittings (input) to the R134a versions (you'd have to do that for the R143a conversion anyway). I think you should probably put in a new dryer as well -- they are not too expensive

maachan · 06-28-2002, 07:12 PM

Any input from Lawrence?

Maachan

Lawrence Coppari · 04:56 AM

Been at Road Atlanta track event. Just getting to reading lists now.

In 1996 my 1980 450SL began leaking slightly. Because R12 became unavailable I started searching around. I bought Duracool and charged it without changing anything. It has worked fine ever since. It takes one can a year. The R12 eventually leaked out. The SL is my daily driver.

Two years later I put it in my 944T. It worked fine there as well. The 944 was originally a R12 system also. Last summer my AC clutch began popping fuses. I replaced clutch with a rebuilt one. System worked well for another few months but then AC compressor main seal began leaking. My feeling is that it was a coincidence or it didn't like the tapping on the clutch to get it positioned. I doubt the Duracool had anything to do with the failure of the seal.

I have never tried it in a 134 system so I cannot speak to that. But no modifications are needed with an R12 system.

I do know that if you overcharge the system, it will not work properly.

I have not gotten around to the seal on the 944 yet because I have another car apart at the moment.