Adding Factory AC to my NON AC 1956 Cadillac

[chstitans42]

I got a lead on a "complete" 1956 AC system close to me for a decent price. Since my 1956 SDV did not come with AC I was considering pulling the entire system and adding it to mine. With that thought I have a few questions.
1. This car is a regular sedan with AC and mine is a sedan deville. Are there any differences in AC system components between the two series?
2. I remember seeing the glass tubes in the rear package tray plus headliner vents in the regular sedans, but not in and Coupe or Sedan DeVille I have ever seen. Is that the only difference?
3. Has anyone ever made a list of all the components needed? Also is the wiring pretty easy to add into my existing harness?
4. I have heard of people putting modern AC systems in their cars, but I have not seen one for a 50s caddy. Is a stock system the best way to go?
5. What would you consider a good price for the system if it is complete?
6. Are there front AC ducts? or does the blower motors in the back shoot air hard enough to cool the people in the front seat?

Thanks for all your times and helping me out.

Thanks!

[Scot Minesinger]

This topic was discussed on the 63/64 Cadillacs recently, and adding a/c to any Cadillac 64 or earlier is fairly challenging, but probably worth it if you are going to drive and enjoy it for some time to come.  Things to consider:

I think you are better off to try and recreate the factory original a/c system rather an obvious aftermarket, and the under-dash add on to me is a hideous disaster.

1.  You will need to upgrade cooling, with fan shroud, higher capacity fan and maybe an improved radiator.
2.  Mount compressor and have the pulley set up to power it.
3.  Fuel pump should have a return fuel line to avoid vapor lock. (need fuel tank with return line capability)
4.  Upgraded alternator

5.  Also the rear differential was lower and I would skip this step of the modification.

All of this is under hood, under carriage work and your donor car should provide all that you need to get started with this.

Then you need all the dash controls, and cables which also your donor car should have.

Use the trunk mounted unit and evaporator air distribution system that your donor car included.  You should probably replace the refrigeration lines with new rubber.  The rubber barrier hose is sold on line and you can take the fittings with hose to an a/c shop and they should be able to crimp them for you.  I have one of those a/c hose crimpers and they are $300.  Just takes one job to pay for itself.

What ever the donor car came with for evaporator air distribution I would use on your car.

If you do this yourself, there will be many might as wells along the way.  If you hire the work out, be very careful on who you select, would be way better if you did it yourself.  This should be a nice winter project.

Enjoy your Cadillac.

[55 cadi]

Hello,

Love watching your videos.

I live east of Dallas with a 55 coupe.

You have a couple issues.

63-64 cads are very different

First you don't need a new fuel pump, they don't come with it for 55,56  no return line even in A/C car, I should know I have an all original.

You don't need a better fan or a fan shroud.

And no alternator, the stock generator will work fine for A/C

1 no there are no A/C system stuff in the dash area. So no worries about that, will explain how air gets there in #3

2. The A/C system needs fresh air intake for the unit that installs in the trunk,  you could cut your own holes and buy a pair of A/C intakes off the internet to fix that issue. If you want to do something like that. In your picture you show it the scoop, if you get it I saw in your car you would need to cut the holes, so just make a template of the holes and your fine

3. The plastic ducts you are mentioning, you don't really need, I have seen some models with have a directional vent mounted to the rear deck, so the cool air goes in to the cab from there, the plastic installed cars, there is a special headliner, it has an opening at rear for the plastic tube to go into and then there is a duct that runs along the top inside the headliner and comes out of vents in the rear and front for all occupants.

4. The A/C controls mount under the dash so that is no problem.

5. The A/C condenser and radiator mounts in front of car radiator and there is already room for that, so no problems there.

6. The A/C generator you can buy the brackets on the internet to mount it where it goes.if it doesn't come with it.

When I say internet I have seen on eBay all of the needed parts.

Hope this helps, good luck.

Any other questions, just ask

Jason

[chstitans42]

Another thing I just thought of was the little electric relay that bumps up the idle rpm. Wonder how well that would work on an edelbrock carb and if you can get one.

[Scot Minesinger]

Yes, the 63 - 64 Cadillacs are different.

The 57 Cadillacs was first year for a/c in front dash instead of trunk, and it did have a fuel return line (same 365 engine) and improved cooling system.  Highly recommend you upgrade to a better cooling system and guard against vapor lock. 

The scoops in back were to allow fresh air, you could just go with 100% recirc. and not have the scoops.

The idle bump up was also to provide a little more cooling capability, you could just set the idle a little higher and kind of get the sweet spot for best optimization of not too high of idle, but a little higher so more cooling is provided.

[Bob Hoffmann CLC#96]

Ben,
Jason gave you lots of good info. My suggestion is this. The ONLY way, repeat the ONLY way to do this job is to have the cars side by side & start switching parts. Also... don't start changing carbs. It just adds another variable which is a PITA  project in its own right.
HTH, Bob

[Walter Youshock]

Air conditioning was available as a dealer installed kit during this time.  It can be done.  I've wondered if the kit included everything the factory installation would have had such as the rear axle ratio.

[The Tassie Devil(le)]

I am in agreeance with most of the above.

If you can get the cars side-by-side, you will see exactly what you need to swap out, and replacing hoses with the modern hoses is the best way to go.

If the donor car is missing anything, make sure you have a list of what is missing, so you can get everything before you start.

Plus, looking at the condition of the Donor Car, I can see you doing a lot of restoration of the parts before you install them.

Bruce.

PS.   Another choice worth considering is Vintage Air, as these units aren't simple under-dash hangers.

[J. Gomez]

Ben,

A few replies/comments to your questions.

1. This car is a regular sedan with AC and mine is a sedan deville. Are there any differences in AC system components between the two series?

Yes and no..!
The differences are the 6219X, 6219 and 6019X have the distribution air duct on both side with the clear plastic funnels feeding them on the rear, while the rest (excluding convertibles) have the outlets on the rear panel. Also there is a different with the fast idle speed-up control one type for the Rochester and another different one for the Carter.
The fresh air scoops were available on all models except 6267X, 6267SX, 54-75 and CC.

There are no differences on the components between the models, compressors, evaporator, condenser, dehydrator/receiver, etc. There was a picture at the Mid-Century Cadillac from Lou with an odd ball evaporator on a 1956 but I can’t seem to find it  

2. I remember seeing the glass tubes in the rear package tray plus headliner vents in the regular sedans, but not in and Coupe or Sedan DeVille I have ever seen. Is that the only difference?

See above

3. Has anyone ever made a list of all the components needed? Also is the wiring pretty easy to add into my existing harness?

You will need the wiring from the donor car to simplify the install even if you will need to redo the wiring. The best option is to take everything you removed from the donor car as you will need them.

4. I have heard of people putting modern AC systems in their cars, but I have not seen one for a 50s caddy. Is a stock system the best way to go?

You can check with Old Air Product in FW or Vintage Air in San Anton.

5. What would you consider a good price for the system if it is complete?

Just a ball part $1,000 plus it all depends on the condition and if the seller is willing to be flexible on $$$.

6. Are there front AC ducts? or does the blower motors in the back shoot air hard enough to cool the people in the front seat?

See #1 above.

There are also a few small things you will need to add/modify on yours once you made the transition.

1.   The rear unit would need to be sealed there should be a panel board at the evaporator with opening for the return cabin air.
2.   The rear seats would need to be modified for the return air inlets, there are two chrome pieces that are place about 2”-3” on both sides at the bottom of the rear seat, about 2”-3” from the floor.
3.   You will need to add a new fuse holder and fuse for the A/C to the fuse panel. That would be one piece from the donor car.
4.   The NSS “violet” wire would need to be spliced as it would need the ground from the starter solenoid to operate the fast idle speed-up control while in “P” or “N”.
5.   The front springs for A/C versus non-A/C cars different, A/C ones are a bit thicker to handle the extra weight for the AC components.

Also jus as FYI,

The evaporator has a thermostat with heating resistance wires to control the temp (part of the control panel) if the unit is damage or the capillary is broken you will need to bypass the function.

The A/C compressor would probably need to be overhauled just be prepare for the price shock in getting these rebuilt.

Hope this helps..!

[55 cadi]

That is one thing I forgot to mention was the fast speed idle up part that mounts to the carb.

Like mentioned I don't know what you would do with the carb you have, if you have a carter you can add that part, other than that you could speed up idle but then your running higher than needed when not using A/C, and even then I don't think it would be working correctly, because that adjust the speed of the a/c generator that makes fluid flow.

Also  the scoops in the rear are for the A/C system, it needs the fresh air to cool system.
Fresh air for cabin you get from the wing vent widows in rear.

You don't want the hot trunk air for the system, that's why the scoops are in place. They are needed for the A/C, that's why non A/C cars don't have the scoops, if they are for fresh air in the cabin they would still be there.

[J. Gomez]

Also  the scoops in the rear are for the A/C system, it needs the fresh air to cool system.
Fresh air for cabin you get from the wing vent widows in rear.

You don't want the hot trunk air for the system, that's why the scoops are in place. They are needed for the A/C, that's why non A/C cars don't have the scoops, if they are for fresh air in the cabin they would still be there.

Jason,

One small correction..!

The scoops are switched for A/C flow or outside air inside the cabin; they are not used to flow outside air to the trunk. The cable control switch is mounted on the back panel to open or close the elbows doors.

HTH

[55 cadi]

I wasn't saying they are to put air into the trunk

It flows through the a/c system into the cabin

I was referring to the post that someone said they don't need the scoops, not sure why non a/c cars don't have the scoops, but a/c cars do.
When you bypass the a/c system it is the same thing as opening the rear vent windows.

I was told that you close the vent from scoop when not running A/C, so you don't have outside air in, and open when running A/C for more air flow because that's the air it cools and blows in. Or vise versa, now I'm not sure

I do know how it is set up and where the switch is on the rear deck,  I have a 55 that has it.

Maybe I worded it wrong?

Maybe I was told wrong?  Makes sense how I was told.

[bcroe]

I would add:
Most cars came with cooling systems inadequate for all situations, esp as they aged.  I
routinely upgrade them for overall performance, even without air.  DO add a radiator
overflow tank & matching cap, which saved me a few times.  The A/C blower might draw
about the same current as the heater motor, and the A/C clutch drain is small, so I never
had to upgrade the generator. 

An under dash unit may not be pretty, but they are a quick way to get a system running. 
The ones I had were quite effective (if no one was sitting front center).  Bruce Roe

[Scot Minesinger]

The rear scoops on the 53-56 Cadillacs did not cool the mechanical system, the condenser was not in the trunk.  The scoops are used to mix fresh air rather than recirc air (on a modern car this is normal (mixing with fresh air), and max 100% recirculation).  You can just have max only 100% recirc and avoid cutting in the scoops.  Yes if the scoops were left open in winter you would get some cold outside air seeping into cabin fighting the car heating system. 

To me the scoops are cool and identified your car as an a/c Cadillac.  If nothing else the scoops could be installed but not used.  The ducting and damper system controlled from front dash will be a pain to install, adjust and all, so I would be tempted to just make it a recirc only a/c system which will also be less work on compressor.

Agree with others, buy the parts car for $1,000 park side by side and make the swap this winter, restoring parts from donor as you go.  Once the swap is made, maybe you can do a neat job removing parts from donor and resell it for a near break even on part cost.  Day one when you receive donor car send out compressor fro re-build.

I still think upgraded cooling (better fan, better radiator shroud) plus the fuel return line are a really good idea.  The heavier springs and different rear axel ratio is not necessary.  If you get stuck in traffic on a hot day you will really want the a/c on and without cooling improvements and the return fuel line it may not a great day of cruising.

Don't forget to consider the refrigerant.  Are you going to use r12, r134, or another type?  This system will be vulnerable to maybe not working on first start up and not leaking either, and then the charge will need to be recovered for work to continue.  Highly recommend the r134, as then just about any shop can recover the charge if you do not have that capability.

This sounds like a super fun winter project.

[J. Gomez]

Jason,

I may had read it wrong too, lack of stimulant at that time..! 

I believe the ’55 has a similar setup, not 100% sure so my statement would be based on the ’56.

The air control know on the rear seat panel has three settings, “on”, “air” and “off”, the scoops are piped at the evaporator housing just above the fans. Inside the metal housing there is a door that is control by the rear air control knob via a cable.

The position of this knob allows the small door at the housing to pass full outside air, or ½ and ½, or fully off from the scoops.

In the “off” position the door is closed to the outside air and cool air while the A/C is running will recirculated back. On the “air” position the doors are about ½ way open which allows outside air to circulate with the cool air, while the “on” position only outside air is circulated back.

Cool air recirculating is from the two inlets at the bottom of the rear seat -> under the rear seat -> behind the rear seat -> and back into the evaporator inlets. 

Position of the air control also plays a role as to where the dash A/C control panel switch is set in “Vent”, “on” or “off”.

I personally believe folks back then did not play with the rear air control knob much as one could forget it on the “off” position and have no cool air circulating or left it on the “air” position and have not enough cool air inside the cabin with the A/C running.

Even the Serviceman #7 from July 1956 instructs in disabling/plugging the rear outside air vents to increase A/C cooling. 

HTH

["Cadillac Kid" Greg Surfas 15364]

Ben/Jason/Jose,
What I am seeing in the donor car is some non factory installed piping.  The vibration eliminator was never intended to be installed in a bent condition, and in the late 50's the shops had to replace many of these because of premature wear and leaking due to their in correct installation.  That said, it is possible that this was a dealer installed kit or some subsequent work done on that system.
That said, Ben, you did not indicate whether you were after authenticity or just a functional system.
Greg Surfas

[Jay Friedman]

I don't know much about early Cadillac AC (as my car is a '49), but a friend, Art Gardner had a '56 with it a few years ago and he told me the following: 

1. The main wire for the trunk blowers and the system in general is connected to the ignition switch, which places a big current load on the switch and can cause problems;

2. His solution was to connect wire this wire through relays he mounted in the trunk so that the current for the system came directly from the battery but was turned on and off by the wire from the ignition switch (or something of that nature).

I suggest you contact him at agardner@gardnergroff.com for more (accurate) details.

[Dan LeBlanc]

Whatever you do, in this instance, where the whole car is presented before you, BUY THE WHOLE CAR.  Don't attempt to harvest the system and leave the seller to dispose of the carcass, because, once it's gone, that's exactly when you'll discover you left behind some obtainium part.

What I would do in the transplant process is start with the compressor.  Transplant that into place.  Then follow the hoses, transplant the next connected component down the line.  Eventually, you will have the whole system mocked up and in place with at least the electrics wired up and some functionality in the system (blowers working, compressor engaging, etc).  Then, once you're sure you have everything, dispose of the carcass and then start rehabilitating your parts.

Seems like a lot more work, but would be fairly idiot proof to not miss anything that way.  If you pull everything, box it up, and then refurbish and install, then you just lose track of how things go together, what fits with what, and it ends up as a hot mess.

[55 cadi]

Thanks for clarifying. Guess the one who told me was partially right/wrong about it.

The inside of the rear a/c box looks like a condenser, and yes I know the condenser is up front, it just looks like a secondary one for which I was not familiar with.

Mr. Gomez I believe you are correct, I just don't understand why the scoop is there which goes through the A/C system and into the cabin if it is only for use when A/C is not on. If it's not to be used with A/C Why are they there when I see non A/C cars without them. Am I not grasping it's use? It sounds like the system still needs the scoops there for the A/C system.

My A/C system is complete and all there, just have not got it working because working on rest of car.

And as far as discarding the rest of the car, how about selling/ parting it out to those who need parts.
Or sell to a place that buys Cadillacs to sell the parts.

[CEC #20099]

Ben Friend: In 1970 I bought an original 55 Cad 62 Sdn with factory A/C. $50.00 driver, in NJ. It was a Florida car. & basically a strippo car. After installing a rebuilt engine & trans, I had a good running driver. I drove it till `73, with the A/C working & serviced.

The system had the chrome roof vents & plexiglas tubes. Tinted Glass. It worked reasonably well , but to a person who is used to today`s climate -controlled cars, it was somewhat crude. Using R-12, it would freeze you out of the car on a 90`s degree day, in NJ. Mine might have had a TXV valve problem, as it would freeze up the evaporator, under high humidity conditions. I switched off the compressor for a short time, letting the evap thaw. Then I switched on the system, & was good to go. THIS SYSTEM WILL FREEZE THE NECKS OF ALL PASSENGERS. If you can deal with this , OK. I didn`t care.

Several things not mentioned were the 2 metal (copper?) lines running under the car from front to back. They had specific brackets, etc, plus the Flexible metal hose behind the compressor. Mine had a 6 blade fan, & didn`t overheat, even though the carb fast idles never worked.

Installing one authentically, today, will be a big job. Universal Metal Hose is out of business. Replacing all lines with rubber makes no sense, at all. The work can be done. Besides the correct parts car, are you an A/C Tech, or a Mechanical Engineer ?? Would help.

Now I have an idea of what the system parts are valued at. I consider that number Low. Good luck.

c chleboun #20099