[Longs]

'67 GTO, I've owned for 35 years, A/C probably hasn't worked in 20 years. The car has all of the original A/C components still installed. The compressor shows signs of leaking oil at the front behind the clutch, the sight glass in the drier is cracked. I don't believe that there's anything wrong with the condenser or the evaporator. I'd like to get the a/c working again.

I would assume that I'd want a more modern compressor (keeping the original), replace the drier. What else would I need to do to have the A/C working? I don't work on A/C myself. Does anyone have any recommendations or thoughts on how you'd approach this system, what would you do to get the best result? Which refrigerant, etc.?

Thanks in advance for any help I get!

EDIT - I realized that I posted this to the 66-67 GTO forum, I meant to post it in Heating & Cooling tech, if someone can move it.

[lust4speed]

Some people might disagree with me, but I was never happy with the 134A conversion on my stock 1967 GTO A/C car. Was very happy once we went to the expense and work to get things back to R12 Freon. I also had crappy luck with the POA substitute tube, and the system cycle from 38 degrees to 54 degrees like a roller coaster over and over again. Found an original POA valve that still worked, and ended up with under 40° temps all the time from the vents. Long battle, but worth it.

Personally, I still think the original A6 type compressor was the best compressor ever made. Its output is something a little over 12cfm compared to the modern compressors in the 6 something range. Old systems need the capacity.

Only thing I saved from the old parts was the evaporator. Compressor, dryer, hoses, expansion valve, POA valve, and condenser were shot and had to be replaced. Still had a lot less in the system rebuild than a new Vintage Air -- but we did all the work ourselves. Probably been a push or maybe a little more money if we had to pay for all the installation labor.

[Goatracer1]

Just a warning, any system that has been open that long is going to have major damage inside of it. If you want to keep it and I can see why, get as many replacement parts as possible.

[aceaceca]

I am doing relatively the same on my 65 GTO. New A6 compressor, new rubber lines, dryer, and going back to freon 12 as I have a drum of it. Before you go too far, check if the heater box doors are working and that the blower is putting out. I have rebuilt my heater/ac box. Basically put two vacuum motors on it and resealed it with 3/16 weather strip. Blocked two knee exit outlets. Sealed the a/c plenum that screws to the front of the heater box. It is a two piece unit spot plastic melted together. The real trick is to clean out the evaporator box
without removing the fender. Fifty years of dirt and leaves have made their way down there. I have used a few methods and am about to re do it with a sink plunger with a hose sprayer attached. Put the plunger onto the inside condenser coils and blast away. Also blast down the plenum that leads to the condenser from under the hood. Use a shop vac with a rig to reduce the hose size. I am also going to check air flows with my new wind speed gauge. I have a new motor on the blower already. I am getting a 400mph wind speed from the impeller prior to it traveling anywhere. I will next check it at the condenser outlet as it enters the cabin/ heater box. I want some real numbers and not just "ooooh it blows really good". I am then comparing data to newer cars. Good luck, I think it is worth doing and keeping it stock.

[Half-Inch Stud]

Installng a 72 AC system onto my 68 GTO. Been dry-fitted and taken off 8 years ago, so it all went on pretty easy this week. All tgether but the Hot Condenser in front of the Radiator. The A6 compressor rebuilt 8-years ago turns smoothly.

Question;
Is there a preferred place to buy the double-flare hose and individual o-ring seals between the condensor to the firewall evap Assy?

[fyrffytr1]

I went with an S-6 compressor because the A-6 kept leaking at the front seal. I went through three of them before going to the S-6. It is a direct replacement for the A-6 but weighs a lot less. They come in a natural finish so I painted mine black. Other than a different style clutch it looks just like the A-6.

[lust4speed]

The carbon front seal in the A6 can be a pesky re-occurring problem. There is a replacement Teflon seal available that is the same design as what comes on the S6 and other new units like the Sanden compressors. I changed over a couple years ago on my A6 and absolutely no leakage since.

Ames has all the replacement parts. I think you can only get the new barrier hose which is a better deal anyway even if you plan on sticking with the R12. I hotrodded a few things in my system so had to have a local hose shop make up custom lengths. I remember that my final cost came out about the same as just buying the kit from Ames.

[aceaceca]

I found this helpful.
http://autoacforum.com/messageview.c...threadid=14922

[compsur]

Originally Posted by lust4speed

The carbon front seal in the A6 can be a pesky re-occurring problem. There is a replacement Teflon seal available that is the same design as what comes on the S6 and other new units like the Sanden compressors. I changed over a couple years ago on my A6 and absolutely no leakage since.

Who carries the Teflon seals...Ames?

[lust4speed]

I ordered out the seal from ebay. It requires special A/C tools and some finesse to get it installed. At least you can touch it without ruining it like the original carbon seal - one finger print on the seal surface and the carbon one will fail. System has to be evacuated to install the seal.

The old compressors have a 14mm shaft while newer ones are 17 -- so you might have to do a little research. Here's the ebay link: A6 Teflon double lip seal

My new manufactured A6 compressor started leaking about a year old, and would toss a little oil path on the fender and hood. I put in a new carbon seal and that one also lasted about a year before throwing oil. Somewhat strange that while they leaked refrigerant oil, the loss of refrigerant wasn't much. Anyway, went to the double lip seal and it's been 2-1/2 years and not even a trace of oil around the compressor.

[Keith Seymore]

Subscribing -

K

[android 211]

You know that reality show "Fantom Works", the owner said something I think is true as pertaining to a/c systems: "we replace everything or we replace nothing". I have a '87 Cutlass, the whole a/c system has always been there; when it was R12 it would blow uncomfortably cold on hot Florida days then I was convinced to go to R134. It was satisfactory out on the highway but around town, low speeds it got barely cool. Stuck in traffic, worthless. I parked it a few years and since then after I got it back on the road its one leak after another. Getting just the right amount of R134 in the system is very important too.

[MUSLCAH]

Great thread

[Longs]

Someone local provided me with the following recommendation:

To keep it simple, I would replace the shaft seal on the compressor, replace the filter/drier and if all the hose connections are tight and no oil leakage is apparent anywhere else, I would pump the system down and see how well it holds a vacuum, (maybe add some oil, too) then charge it with 12a, a Freon substitute that requires no changes to the current system!

It could be worth a shot, in theory it wouldn't be too much money since the dryer needs to be replaced anyway, and the Teflon seal mentioned above could be an option on the compressor. I could install the dryer but don't have the tools or know-how to change the seal in the compressor, and I'd need a shop to check for leaks, etc.

Thoughts on this approach?

[lust4speed]

A week later and it's been very quiet.

I have a friend that tried the Freeze 12, but don't know if that is the same as 12a or not. Anyway, it's performance was about the same as what a 134 conversion would be despite their claims, and he has since went back to true R12 Freon.

As far as using old hoses - one of the reasons I replaced all mine was whenever a hose was moved or the compressor swiveled out of the way to get more room to work on the engine, the system would loose some charge. Even though the clamps on the old hoses were as tight as practical, moving them opened up a path at the fitting.

I would be very tempted to go with the new S6 compressor for your car, and I have seen them in black. Either that, or find a new A6 with the new type seal. Most of us have pretty well proven the original carbon seal has a limited life expectancy.

In this last week we installed a Vintage Air Mark IV system in my blue car that never had A/C. We ordered out the hose kit along with the unit, and borrowed the hose crimper from Wheelspin (Les Iden). The new barrier hose was extremely flexible and was very easy to cut with our Craftsman hose cutter - went through it like butter. We simply set the hose in place, cut it to a good length, and used a silver magic marker to draw a line on how the fitting needed to be oriented on the hose. All the lines went together really easy, and much less hassle than we went through last time driving to the next town to have a hose shop crimp things. Even if you have to buy the crimper, it's only about $160, and it could be resold on ebay to recover most of the expense. Then again, I think Ames carries new hoses already made up properly for the stock systems?

Can't comment yet on the original system in my Cruiser vs. the new Vintage Air in the blue car because I'm still waiting for my friend with the scales and such to come up and charge the new system.

[gpmodelj70]

12a is 80% 134a

[hgerhardt]

One thing that R134a demands is an efficient condenser. Our original round-tube serpentine-style work fine for R12 but not R134a. Just look at any vehicle built in the last 20 years and you'll see most have parallel-flow condensers. Fortunately nowadays you can get parallel-flow retrofit units.

[Longs]

I'm still trying to sort everything out. I bought the Dryer from Ames but nothing else yet. I'm thinking about getting the Pro6ten compressor rather than a rebuilt A6 even if it had the newer design seal. Another key question is R134a versus 12a. I see the consideration about the condenser, the question there would be to take a shot with the existing condenser to see if I can get an acceptable result.

Do I do any harm if I change the dryer then have a shop put a vacuum on the system just to see if it holds? If it does, then I change the compressor and nothing else, if a shop can charge it NOT with R134, and just see what I get?