[dataway]

I'd like to get some responses from those of you who have altered, refreshed, rebuilt (etc) the AC system in your vintage Pontiac.

This poll is for those people still using OEM style evaporator and condenser ... by OEM style I mean direct fit. No under dash systems, no aftermarket systems that require replacement of suitcase components (inside or outside), control replacement etc.

Thanks

[Cardo]

Running a new Alma A6 with r134a and a hollowed out POA valve. Original blower, sealed all of the duct joints and added a ammonia switch to change it to a cycling clutch. I tell you it dumps ice cubes in your lap. My wife has actually mentioned she was cold in the car on a 90 degree day. I'm building another car and will do the same exact thing. Also, when using 134a in an originally r12 system, only charge it to 80% of the original capacity. That is probably the main reason why people have problems cooling when converting. They overcharged the system.

[Half-Inch Stud]

Relative loves the VA in his 56 Chevy.
I had plans to go that route for a non-AC GTO, buuut no GTO

[burd]

My 78 needed a few parts to get it running again, hunted them down, found all GM PCs, my mechanic wouldn’t warranty the fix without a new accumulator. I then sent my orig out to be rebuilt. Which will go back on one day. When he retired, I bought all his ac equip. I like having my own hole in the ozone layer. lol
Nothing looks butchered Evers than ac systems cut off or cobbled together
Stay Orig. My vote

[dataway]

Cardo ... I hear the new ALMA A6 units are "next gen" do you know any details of the changes? My guess is a better front seal for one, not sure what else (besides metric threads). Did you get your ALMA from Old Air ... or another source?

[bhill86]

I went with a system from Original Air Group/Classic Auto Air which included all components forward of the evaporator core. Sanden compressor, and a parallel flow condenser. At this point I can’t recommend this company. The system seems to under perform, I wasn’t happy with the fit and finish of the kit and their customer service is non existent. If you had an issue with an item and needed to return it I’m not sure how you would because they don’t respond to emails or phone calls.

[Cardo]

Appearance wise, there is no difference with the Alma. It does have the new seal on the shaft. Metric thread wise, the only thing i know of would the bolt that holds the lines on the compressor in the back. When the compressor comes, there is a plate bolted over the holes, and the compressor is actually holding vacuum. When I pulled the plate off, I think I just reused their bolt, or was at least able to get a size off of it. I called them and talked to their engineering department. They were extremely helpful and based on my application gave me the part number of the compressor to order. They are built to order, so it takes about 3 to 4 weeks to get one. They gave me the number for a Thermo King in Michigan to order through. I will most definitely use them again for my next build. My system has been filled for 4 years now and not leaked at all. I know this for certain because I just had to draw my system down this past week because I noticed i had a line slipping off at my condenser with a hose clamp, and needed to loosen it and push the line back on the rest of the way. Tragedy averted!!!

[cleveweld]

The Factory Cool-Pack A/C system on my 62 Tempest has been completely rebuilt. The original A6 is rebuilt using green o-rings which are correct for use with R134a. I replaced the original ceramic shaft seal with a double lip rubber seal. The 6-7/8" pulley, bearing and clutch are new. The large diameter pulley was used on the 4-cyl. engine.
All high pressure hoses are new. The temperature control valve is rebuilt with a new diaphragm and new green o-rings throughout system. All parts of the A/C system are original. Even the round slotted high pressor hose clamps are the originals.

The A/C fan motor is located under dash. The system blows cold air but the fan doesn't have a lot of volume to it.

I bought a refrigeration vacuum pump and manifold guages a few years ago and service my own cars.

[1965gp]

I went with the factory style parts (I think from old air in Dallas?) o our 79 TA and it just doesn’t perform like the vintage air in my other cars. If the car is rare/valuable I totally understand keeping it original, but if not go with vintage air or a similar system. I was amazed at the difference.

[66sprint6]

I had all of the old A/C parts that came in the trunk of our '67 LeMans. They were very old and I wasn't sure what to do with them. I saw a video where some guy just assembled them on his '67 Chevelle, pulled a vacuum, and filled it. I decided to try that with the old pieces that I had. I reassembled everything, with new seals that I got from a guy on the web called "The Parts Guy". I was lucky, I found a local guy that had a 30lb bottle of R-12, which I still have. I pulled a vacuuum, left it for a while and found no loss of vacuum, weighed in the proper amount of R-12, and the system works beautifully to this day.

[gto4ben]

I kept my '67 GTO AC system all original using R12 and mineral oil. Each component was checked and bench tested for operation, pressure and vacuum leaks. I used the HNBR (hydrogenated nitric butadiene) rubber O-rings (green) for the tubing joints, receiver-drier inspection glass, and compressor seals . I also upgraded the A6 shaft seal from ceramic to double lip. Hoses were replaced with are the barrier type Goodyear Galaxy version, including the liquid line from the receiver-drier to the expansion valve. Each component was flushed prior to assembly. POA was checked and reset to 29psig.

FYI, the evaporator oil return line has a special schrader valve in the POA. I never found any OEM new ones but compression testers use a low tension valve core that is very close if you need to replace a missing one. Milton 1251-2

I hope you find interesting the bench testing and data photos of the expansion valve and POA. The POA tested was stuck and the input and output read the same pressure. Once freed, the POA began regulating as shown in the gauges pressure difference.

[Ben M.]

I put a modern Pro6Ten compressor on my '73 wagon and used R12. It would cool down to 40F out the vents in the hot and humid Appalachia summers. It's still working to this day (9 years later).

[Bruce Meyer]

The Pro6ten bolts to the factory brackets. Its way lighter than an A6 and draws way less horsepower. I use R12 with my cars. I changed the oil out to R12 compatible oil. They work great even here where it gets over 110 F.

[gtospieg]

I also have the pro 6 ten compressor in my 67 GTO. New evaporator, condenser, hoses, dryer and everything else too, including a rebuilt POA. Finally had it blowing 43* last year after several years of no luck. While I was driving the car I did a high speed acceleration and now the air won't go below 50*. What the ??? Why?....Current build is getting Vintage Air.

[lust4speed]

I spent a lot of money restoring the original AC system on the red '67 GTO. Someone had converted it to 134a and that simply didn't cool very well. We replaced everything with new parts and replaced the cycling POA eliminator tube for an original POA valve and went back to R12. Was a comfortable car in the Summer heat but never once thought about turning it down from max cooling on hot days. Sold the car and that left me with my blue '67 that was a non-AC car. This time went with the Vintage Air Mark IV system since it would be easy to bring back to stock and the heating was working fine. It's been over five years and the VA system still freezes me out and within a mile or two of hitting the road I'm turning down the fan and cutting back on the temp control to avoid frostbite.

Now in the process of getting the AC to work on the '65 Catalina wagon. It is still an R12 system and except for a slow leak it was sort of working. Replaced the old A6 compressor that was tired and had a leaking front seal with the Pro6ten unit after flushing out the PAC oil it came with. Replaced all the hoses and the evac valve and confirmed the POA valve was functioning properly. Wasn't a bad project but took all three days of the long weekend. Have a few problems to resolve but think it will be fine. Lots of square footage to cool with the big wagon so it needs to be on its game.

[ta6point6]

I switched to a Sanden compressor 134a in 79 Trans Am and the rest was all original condenser and evaporator. It feels plenty cool but for me the real problem is the fan motor moves to slow compared to modern vehicles. On hot days the car is on max cool and high fan which can get annoying at times.

[dataway]

Excellent input folks.
I'm seeing performance of the systems kind of all over the place no matter what type of system is used. Makes me wonder if some vehicles designs are more suited for AC than others. Like how well things are sealed at the core support, how well the OEM blower fan works, ducting etc.

Cleveweld ... love that setup, what a nice restoration. Always loved the under dash units. When I was a kid my parents had a 66 Tempest with a Sears under dash unit installed ... like a freezer.