OK have fought my factory air all summer, finally retro fitted the stv and got it working pretty good :hurray:then on a road trip that i got the wife to go on with me the #$%@compressor bit the dust:mad: so my question is do i replace with a rebuilt A6,sandon or do I order a vintage air type system and have an A/C that really does cool the car?

OK have fought my factory air all summer, finally retro fitted the stv and got it working pretty good :hurray:then on a road trip that i got the wife to go on with me the #$%@compressor bit the dust:mad: so my question is do i replace with a rebuilt A6,sandon or do I order a vintage air type system and have an A/C that really does cool the car?

I'd keep the factory air, but replace the cpmpressor with a Seltec or Sanden. Check these guys http://www.autoacforum.com/ they sell parts/eqpt/supplies as well as provide the very useful mobile AC forum for questions/answers etc.
My $0.02

I have Fac. A/C on my 70 driver. After screwing around for a year or two, I sent the POA valve to Tampa, Fla. ( $15.00 shipping and $15.00 to have it adjusted for 134 ) Cleaned out the system and charged it with 134. Remember use 85% of the factory recomended charge when using 134.
I have a rebuilt 70 style compressor from Advance, Blows very cold on the open road not perfect in town. WHY ?
If you look at any new car/truck, The condenser has SMALLER Tubes and a lot more than early G.M. condensers. The 134 gas needs a lot of air going through the condenser. Right now my 70 is 100% all factory parts and will freeze your butt of on the highway. If and when someone builds a 134 condenser that will FIT without chopping up the 70 front end, I will go that route. I may go junkyarding to find a condenser that may addapt to my 70.
When I drove from Pittsburgh,Pa. to the MD. show I ended up with the four speed fan on the two positition and the wing window cracked open a bit. Also my ride is a 70 Vell WAGON. When all items are in concert you will be COOL !
Bob

Have you thought about a universal-fit parallel-flow condensor?

http://www.ackits.com/c/Parallel/Parallel+Flow+Condensers+-+Aluminum.html

I have recently purchased and started installing a new Vintage Air kit. It is the new gen IV system that uses the factory controls. I really like the ease of install so far, but my car is gutted in the middle of a resto. Its going in my 65 2 dr wagon.

But, If I had an original A/C system, I think I would make it work.

It sounds like you've been patching up the original, 45 YO system and are now frustrated when the next weakest link gives out. Old MVAC systems that haven't been maintained throughout their lifetime are an "all or nothing" repair. Anything less often leads to disappointment, as you found out.

With that said, I would still keep the original system. You can rebuild your system for just about the price of an aftermarket system and still retain the originality and functionality of the old system. The refrigerant loop in your old system is far more robust than any aftermarket system made today, with a significantly higher BTU capacity.

Also, ditch that STV retrofit and source a rebuilt STV, or have yours rebuilt. It's the heart of your old system. That eliminator is actually a downgrade.:(
Approach rebuilding your original AC system as you would approach rebuilding your original engine, trans, rear end, etc. No shortcuts.

I'm a big fan of the A6 compressor, so I'm admittedly a bit biased. Brand New A6's are available for about $350 or so. That's in the same ballpark as new Sanden or Seltec compressors, not including new mounts. You will also need custom hoses to attach to the other units. The A6 has a significantly higher displacement and is a stronger unit than both the Sanden and Seltec.

If you are intent on replacing the A6 with something more "modern", there is a direct fit unit called a Pro6Ten. It's a Sanden compressor with A6 mounts and line connections. Ecklers carries it, but doesn't use the Pro6Ten name:
http://www.lategreatchevy.com/product.asp?pf_id=551067&dept_id=1184
They have been on the market for about a year, so I can't say much about them. It's a great idea, though.:thumbsup:
Here's a discussion on another forum about it:
http://www.cadillaclasalleclub.org/forum/index.php?topic=104071.msg124594
Pay attention to the post that talks about the BTU and volumetric efficiency of new compressor vs the A6.

Condensers=:confused: ?
As you mentioned, try and find a parallel flow condenser if you plan on using R134a.
PF(R134a) condensers are more efficient than earlier serpentine types, which are more efficient than the even earlier Tube and Fin types.
Check out the universal PF types and see if one can be installed without too much mounting modification.
If not, even an 80's-90's, R-12, serpentine type condenser would be more efficient than your current "tube and fin" style from '65, with R134a. That can be a fallback position if you can't find a suitable PF type. You'll just need to concentrate more on airflow over it to get good cooling.
Either way, you'll likely need to modify the AC lines.

At this point, may I suggest keeping your rebuilt original system R-12?
It was designed for R-12 and if it is rebuilt correctly, you'll get many years of service from it before it needs "topped off" again.
The price of R12 has fallen drastically in the last few years as the demand has dwindled. R12 can be had for $12-15/lb, as opposed to $7-10/lb for R134a. (This assumes DIY. Most shops bought their current supply of R12 when the price was in the stratosphere, and charge accordingly.)
Thanks to folks that hoarded tons of R12 in the 90's hoping to cash in "later", there is still a huge supply. Most missed the "peak" price and are trying to unload it before it is nearly worthless.
Think about this:
Most R12 cars have now been turned into Chinese razor blades and other crappy products. Of the remainder on the road, many are deemed too old to fix the AC system. Of the remaining cars with viable AC, many have been converted to R134a. The actual number of pre 1993, cars with working AC (and R12) on the road is miniscule today. The current supply of R12 will likely last well into the next century.

Just some things to consider. I hope it helps in your decision.

Edit:
+10 on checking out www.autoacforum.com !! It's a great resource for DIY'ers who have questions about the AC system in their cars.:thumbsup:

Thanks for the info, you hit on some very good points. what if I were to keep the stv upgrade because i'm thinking I may have discarded the parts it replaced? Will this hamper the performance? And I would have no problem going back to R12 as you mentioned the price has come down.I can purchase a rebuilt A6 from my local carquest for around $110 (they shot me a very good price)and i feel this would be the way to go just bolt it right back into place.

To do the job right you need to budget about $1000. Remember, you were considering spending $1000-1200 on an aftermarket system. If it takes less, have a few beers and spend the left over cash on other parts for your car.

Let me repeat, "Also, ditch that STV retrofit and source a rebuilt STV, or have yours rebuilt. It's the heart of your old system. That eliminator is actually a downgrade. " You need the STV in the system, because the system is designed around the STV. The eliminators are a very poor way of making the system "work".

Did you look at the link to the Pro6Ten discussion on the other site? They also go into issues with Reman A6 compressors. Basically, reman A6 compressors are a crapshoot as far as longevity. This is probably because the cores are 30-50 years old with questionable history. Buy a NEW A6 or the Pro6Ten and be done with it.

Here's some other things that need to be done
-Replace the Thermal Expansion Valve
-Replace the receiver/dryer.
-Make sure the STV is caibrated for the refrigerant you plan to use.
-Remove the evaporator and have it pressure tested. Clean and reseal the evap case when you do this. If the evap shows signs of corrosion, replace it. (A new evaporator for your car is about $300, I just replaced one).
-Have the condenser cleaned and pressure tested.
-Send the hose assemblies out and have them rebuilt with new rubber hose.
-Replace any metal lines that show signs of corrosion, fatigue cracks or damage to the fittings.
-Thoroughly solvent flush all of the used components.

If you do the job right, you will be very happy with the results. If you cut corners, you'll likely have issues down the road.
Good Luck.

STV system---What does STV stand for? Is it only only early models such as 65's? I have a 69 and in process of replacing everything so what is STV?

RwS

STV=Suction Throttling Valve.
The STV maintains the evaporator pressure at a set point for proper cooling. They were used through 67 or 68.

Your 69 will have a POA valve. POA= Pilot Operated Absolute Valve.
It does the same thing as the STV, just a newer design. Be sure to have your valve tested and calibrated when you rebuild your AC system. Used from 67-68 up through the early 70s.

Later GM cars used a VIR assembly. VIR=Valves In Receiver. The POA valve is incorporated into the receiver/dryer. Used in the mid-late 70s.

Modern CCOT systems (Cycling Clutch, Orifice Tube) cycle the compressor off at the optimum evaporator pressure. The pressure then rises and the compressor cycles back on. This method "works" but is a crappy, inefficient way of doing it. This system started in about 78 and is still used today.

CCOT is also the idea behind STV/POA "update" kits. Converting a POA/STV system to a Cycling Clutch system is actually a downgrade.

The Frigidaire/Harrison POA system is thought by many to be the best MVAC system ever produced. The STV system is a close second.

OK, Thanks, I just purchased an exchange POA rebuilt valve for the 134a from the place in Florida. So I should be set for the 69. But what is this about the 85% of required refrig.to be put in. Why is that?

RwS

OK, Thanks, I just purchased an exchange POA rebuilt valve for the 134a from the place in Florida. So I should be set for the 69. But what is this about the 85% of required refrig.to be put in. Why is that?

RwS

Due to the less efficient condenser in older R12 systems, an equal amount of R134a in the system can cause the high side pressure to be excessively high. 80-85% is the recommended starting point when charging a converted system. Often, this is just right to get proper cooling, it varies from system to system.
The charge amount can be be tweaked, while watching the high side pressure, up to the original R12 amount. This will depend on airflow through the condenser. The more airflow, the more heat that will be removed. The more heat that is removed, the lower the high side pressure will be.

Thanks for the info. About to replace every component on a factory system that I changed to 134a but been fighting with it to make work in past years. Hope this does it.

Thanks again,

RwS