Ready to tackle the dreaded A/C issue. I have had my Cab for ~6 months and have not been too concerned about the A/C, which the previous owner had never had functional in the 2.5 years he had it. Of course, now it is getting HOT and it is becomming and issue. (I just drop the top, but the wife isn't entirely happy with that solution )
From what i can see it is all original - compressor, hoses, condensor, R/D, etc. It is an '88 911.
1. What are the chances that if i can find a shop that will charge it with R12 (or one of the supposed replacements like FREEZE12) that it would actually work?
(I assume the R/D is shot at the least. While the hoses are not deteriorating, they are OLD. Is it for sure that the compressor is shot?)
2. Could I replace things myself like the hoses, R/D, and compressor and THEN take it into a shop for the vacuum flush and refill? Would this be enough?
3. Has anyone replaced their hoses - it seems like a daunting task!!!
4. I see that places like Pellican sell kits - anyone recommend one?

I appreciate any advice that will help me keep cool without spending thousands!!

 

there are lots of problems with the original A/C from the factory. One of the biggest problems is the original hoses aren't able to hold the R12 or 134 (are those the right numbers?). Barrier hoses are the answer there. Another is that there isn't enough capacity to really cool the car so many of the aftermarket kits out there focus on expanding the evaporative, condensing and drying capabilities. I've investigated some of the vendors and www.griffiths.com and www.rennaire.com seem to get the most attention. Many owners seem to think the compressor is usually the least of the problems.

Can you do it yourself? If you're pretty good mechanically and nimble too I'd say you can. I've toyed around with doing it myself but I'm leaning toward just taking it all out and losing the weight.

 

Found the first problem today - the forward condensor blower motor is seized. From what I understand this will only decrease the efficiency of the system - but it will be replaced anyway.

I did have a question from the book '101 Projects for your P 911' - it mentions making sure the 'electromagnetic clutch is engaging' on the compressor? How do you determine this? (I'm new to this!)
rbuswell - thanks for the links! I like the rennaire kits. There isn't anything i won't tackle, provided it can be done without lack of experience potentially causing damage.

 

I think you only have to start the car and run the A/C while watching the compressor. You should see it kick in and out as it's working. Any one else want to chime in?

 

Hello,
(sorry but I don't know how much you know, so please don't take offence)
The electromagnetic clutch is on the compressor and it is the pulley that is driven by the belt.
The pulley is made up of two main parts that are joined by the electromagnetic clutch.
The part the belt is on spins all the time the engine is running; when you turn on the A/C it is joined via the clutch to the main compressor shaft, making the whole thing work.

If you have a look at your compressor you should see a wire going into the back of the pulley. This could be one or two wires as sometimes the clutch gets its earth (-) though it’s mounting.
To test:
With the engine not running but the ignition on and the A/C off, go back and have a look at the pulley.
Then have someone else turn the A/C and the fan on while you watch it. (Do not start the engine!) When they turn the A/C on, you should hear a click from the electric clutch as it engages.

If your system has a “low pressure” switch, and you are out of gas, you will need to bridge the “low pressure” switch in order to perform this test.
If there is no gas in the system the “low pressure” switch stops the compressor from getting power so it doesn’t destroy its self.

I hope this makes some sense. Good luck

 

psychoideas, Thanks! Certainly no offense taken. This is exactly what i needed to know. I just went out and did as you described. Seems that my electromagnetic clutch is working. I appreciate your very detailed explaination.

 

FWIW, I just had the A/C charged on my '89 Targa. The shop pressurized the system and left it for 4 hours- it didn't leak at all, so they charged it with R12 and now it work great. So I suggest a pressure test when you get stuff fixed, and yes, there are shops that will charge with R12.

Good luck!

Paul.

 

Answers:

1. There are still plenty of shops that will install R12. It's pricey, though. Most shops will not work with Freeze 12 or similar substitutes, and will not service cars that have been converted.
2. Yes. The compressor might still be good. If not, it's a common compressor and many a/c shops have rebuilt units on their shelves. I replaced my hoses and compressor, and replaced the R/D with a ProCooler, and had a local shop vacuum it down and intall R12. I'm getting mid-30 degree temps at the vent.
3. Yes....you can replaces hoses yourself. It's a messy job, but very DIY-able. Pelican sells a kit from Rennaire, which is very reasonably priced. In fact, if you're considering R-12 you should absolutely replace the hoses before have the system recharged. Otherwise, your expensive and ozone-depleting R12 will leak.
4. You may not need anything more than hoses and an R/D (or Procooler). The compressor might still be good....and at the very least you should have a local a/c shop check it out before you spend mega-dollars on a full kit.

I hope this helps.

 

To get your a/c working is a good thing for your particular year. If you had an older 911 I would suggest that you not bother. The key issue to air in 911s is air VOLUME and MOVEMENT. Earlier ducts were just not capable of moving enough air to make a difference. After 1985 the ducts got the first substantial upgrade in dimension. Over the years Porsche took a far better approach to dealing with the environmental issues in their cars.

 

The next step is to check for leaks. Have the shop vacuum or pressure test. If you have a sealed system, then go ahead and have freon put in there. You can change to barrier hoses if you want or just plan on refilling it every 2 years instead. Replacing the front condenser blower is only $100, so it's worth it.

 

can we get R-12 in so. california? The first place I asked told me to check in Nevada or go to R-134 so I gave up on the idea of having air.

 

Last time I checked, we could. Try another shop in your area. I used Lucas Auto Air in Van Nuys.

 

The problem with this plan is that the original, or non-barrier hoses, are designed to leak. Why install expensive and environmentally unfriendly R12 if it will just leak out anyway? With the cost of R12 so high, and the damage it does to the ozone, I think it would make more sense to install barrier hoses BEFORE refilling the system.

 

You can go to almost any auto parts shop and buy the adapters to convert the system to the new R-134a. You can also purchase cans of R-134a and a fitting and gauge for charging via the "low" side valve.

All for under $50 DIY, 6 - 8 ounce cans.

 

This will work, but (a) you won't get cold (sub-40 degree) temps, and (b) you'll likely be refilling the system on a regular basis as R-134a leaks faster through the non-barrier hoses than does R-12 (it has something to do with the size of the compound's molecules). Also, if the system has a leak there may be air in it already, which would require that the leak be fixed and that it be vacuumed down.