Air Conditioning Upgrade

[bobbigham]

I have a 88 targa and the car is basically perfect. Runs great, exterior and interior are about perfect, everything works great.....except the a/c. It slowly leaked R-12 when refilled about 2 years ago and now the compressor is starting to sling some oil...

What is the best route to fix it? Replace the compressor and find someone to recharge it, or install a new upgraded system?

Anyone done an upgrade, what would the cost of that be?

Has anyone installed a upgrade kit, if so cost of parts and how much work is involved. I'm not mechanical expert but can do some basic work, not sure if I could handle the install myself, just wondering if someone could give me some advice.

[theiceman]

this has definitely been done .. with varying degrees of success .. rennaire seams to have a good kit. I owuld suggest waiting to hear from our Texas listers as they seam to have it down to an Art .. here in October in canada .. I can live without A/C ,,,, could use a good gasoline heater though from an old bug

[rusnak]

My own $.02 is that if you can still get R12 and you don't have a problem with the car running too hot, you would be better off finding and fixing your leak, and recharging w R-12. The compressor can be rebuilt. You can also buy a compressor already rebuilt.

[bobbigham]

Finding reputable places or mechanics with R-12/ or willing to re-chrage the a/c with R-12 is getting difficult, more so than getting liquor during the prohibition era....I can only guess I'm not that old.

I may consider a replacement compressor, but will need to figure out where/why the system is leaking.

[theiceman]

but there are all kinds of legal r-12 compatible substitutes now available.

[rusnak]

You can try pulling a vacuum, after replacing the o-rings at the hose ends. I have heard of problems with freeze12. I have the 134a stuff because it's cheap and plentiful. It works ok on all but the hottest days, and the engine will run much hotter, so it's a pain in the butt. I requires changing the xpv and doing an evac to change the compressor oil.

[whalebird]

Recharge with R134 and let it go. just put a can back in every so often as you need. forget all of the conversion conjecture that everyone has an opinion on. Just recharge with 134 and add a bit of oil (most important to use oil compatible with R12 and R134). If you have a major leak, use the 134 to diagnose and repair/rebuild at your discretion.
You will never have great a/c in your car without dumping major cash on it. A 964 front condensor/fan unit will go a long way, but cost $$$.

[bobbigham]

I'm getting a little lost.

It sounds like a full conversion to a 134 system isn't really a great idea considering the $$$ involved just to get a slight improvement.

I know I will have to change the compressor, but before I do I want to have a plan. I also thought you had to replace the condensor as well (not sure why). And can you use the same new/ rebuilt compressor for either refrigerant system?

What is pulling a vacuum (how do you do that?). I thought they used to use a color/dye, inject it into the system, run it and see where the leaks are???

And when you find the leaks, you tighten fittings, replace Orings or lines, etc??? Then recharge with some alternative refrigerant. (I'll do some research on that).

Yep...almost completely lost now.

[rpidduck]

I had a full Griffith Keuhl system installed in my '85 last summer, not cheap but effective. At ambient 90 degrees measured 45 degrees out the center vent, very satisfactory. My compressor was ok, and a PO had installed the newer serpentine evaporator already, but still $2 grand plus in parts and hoses. In So Calif AC is needed to get full utility out of car, maybe like Georgia.

[rusnak]

Bob,

Conversion to 134 is not expensive. It is cheap and basically involves changing your receiver/dryer, changing the expansion valve to a 134 expansion valve, flushing the system, changing the high and low pressure valves on the compressor, and evacuating the system before filling w 134a. This all can be done at home with the right parts, then you can take your system to an ac shop for the flush, vacuum and recharge.

However, it is not an upgrade. I think R-12 is way better if you can continue to buy it. I had to compensate for the less efficient 134a by installing a Pro-Cooler. You can keep your stock compressor, but it it is leaking you would definitely want to have it rebuilt. The o-rings fit onto the stock hose ends. You remove the hoses, then install the inexpensive viton o-rings. You can buy the o-rings at most automotive parts suppliers (Napa, Kragen, Autozone, etc). Opinions on dyes and stuff vary, so I'll stay out of that debate. If the hoses are leaking R-12 you'll want to replace them. 134a is comprised of a smaller molecule than the R-12, so it will actually bleed through the hoses, and that is why 134a can use R-12 hoses if you are willing to recharge every year.

This is the route I went, and basically I have my own vacuum pump and refill valves. Every year I pull a vacuum for at least an hour, and recharge w 134a. Periodically I add a small amout of pag oil.

[bobbigham]

Thanks for all of the information guys.

It seems that I am going to have to replace my compressor anyways, then consider the new parts outlined above as well.

There is a kit from Rennaire that includes evaorator, expansion valve, dryer/ receiver, hardware, oil, hoses and Sanden 507 compressor for $1250.

The cost is higher (about $229) for a OEM NippenDenso compressor, not sure if it is worthwhile as the Sanden includes an alumimum adapter plate, and is smaller and lighter weight.

I know I need to review the manual and see where all of these parts are....

I am not a Houdini and can't bend like Gumbi any longer, so can you get at and replace most of this stuff easily by putting the car on jack stands? Or is it a winter project versus a few weekends?

[bobbigham]

Reviewed my Bentley manual. Lots of good detailed information. It looks like most of the parts aren't too hard to replace, except maybe running new hoses beteen all of the components...that could be a project... maybe.

I would also need a recovery/recharging unit/equipment...not sure of the cost of that? More research....

So far the rennaire kit w/ compressor is at $1275, the recharge/recovery equipment (?), versus the cost of a complete install w/ parts at $2500.

I'm guessing my cost issues are running up because I need to replace the compressor and possibly some lines/hoses and a receiver/ dryer and evaporator and expansion valve at a minimum? Starting to add up anyway.

Any other suggestions?

[rusnak]

I still have my stock ac hoses, a few hundred bucks worth of parts, and do my own recharge with a Robinaire vacuum pump.

[wwest]

I have had several of our company cars professionally converted to r-134 for a cost as little as $100, but mostly sub-$200.

Our '88 Carrera has had to be recharged with R-12 just about eevry 2 years. This next spring it will get converted to R-134 and I do not expect to need anything other than it vaccumed down and filled with r-134 and oil as required.

[911 cab]

Let me know what you decide to do.

I am in the same situation, 89 911 Cab looks and runs great, but summers in Georgia are tough without air.

911 Cab