Installing Classic Auto Air in a '70 Charger

[Kern Dog]

With the Summer not too far away, I want to get the system working properly again.
I added the refrigerant 6 weeks or so ago but testing for cold air when it is 45 degrees in the shop wasn't telling me much.
Rooting around in the shop, I found this stuff:

I borrowed this from a guy that later moved out of state. I've had that happen before in another way. Back in my construction days, sometimes I'd borrow a tool from some guy that got laid off and left early without his tool.

30 lb tank. I guess this can be refilled? I have no intention of refilling 15 cars like a full tank of this kind would allow but I'm guessing one could just get a partial refill?

Of all the videos I've seen, they all look similar. Blue line for the low side, yellow for filling and extracting, red for high side. NONE of the fittings fit any of the other ports, they are unique.

To evacuate the system, a vacuum pump like this is necessary.

I've learned that the condition where a system sits at a high level of vacuum somehow generates heat that eliminates the humidity and contaminants in the system.
I may just play this by ear....I may only do leak testing, I may take it further and actually fill it too. I'm curious about why it lost pressure.
To recap:
I installed the system in late 2019. It took until Spring 2022 before I had it charged. I went to a BMW repair shop owned by a guy that I've known for years. I've framed the roofs on 4 of his homes so he was kind and did the job free.
The guy that charged it did not follow the stated procedures where the system had to be sitting with a vacuum for 30-45 minutes. He didn't charge it with the engine off. I don't know if he even used the exact amount of refrigerant. The guy doing the work was an employee of the shop, not the owner. Some mechanics are like Doctors where they don't like to be told what to do.
The air blew cold afterwards so I figured that we dodged a bullet.
The instructions state....

If I need a new compressor, so be it but that doesn't explain why it loses pressure. If I can put a vacuum in the system and if it holds, at least I know my ugly hose crimps are actually holding.

 

[Kern Dog]

I ran it again today. Damn the heater works great...plenty of hot air coming through the vents.
When switched to A/C, it just blew shop temperature air. The compressor clutch turns all the time, I guess that is normal for this system?
With the engine running, I pulled this wire:

......and the engine stalled. I was wondering how the ignition could be tied into the A/C system. I reconnected the wire plug and then cranked it over. I couldn't get spark. It didn't make sense.
I swapped in an orange box ECM and it fired right up.
Okay, bad chrome box? Maybe, maybe not. I swapped the chrome box back in and it started up normally. What the heck did I do??
At least I reconfirmed that the A/C isn't blowing cold. I need to hook up those gauges and see what the pressures are.

 

[Kern Dog]

Oh, the difference’s between this system and Vintage Air….
It is strange how two companies selling similar products have opposing views on some matters.
VA instructs to put their heater control valve in the lower fitting on the evaporator unit then eventually to the manifold, as if a 440 has a heater fitting on the manifold.
Classic auto air instructs to put the heater control valve to the top heater core fitting then to the water pump.
Then there is this detail….

The guy that did the service to my car didn’t do step 1 or 4.

Now, I understand what it can be like to have some set of instructions seem stupid and pointless where the mechanic just proceeds to do the job the way other cars get done. I’m curious if this is what caused the trouble. The compressor makes no noise like anything is rattling inside.

 

[davek]

I would lose my mind reading that. Is that how they did it way back when? Ive always ran the car when filling it.

 

[Kern Dog]

I’m confused by it too. They state that the compressor will be damaged by charging the system the conventional way yet they use a standard Sanden compressor.
I should call them tomorrow and see if they can explain that.

 

[gtxdana]

You can charge an A/C system either as a liquid or a gas. Engine running or stopped. Of course, it does make a difference which side of the compressor you're putting the freon in as a liquid or gas.

 

[Kern Dog]

The picture below is during the mock up but it is how it looked when finished too. The #10 line off the firewall is in gas form since it is after the evaporator. It has the charge port in it like shown in the instructions.

The high pressure side is over here:

That is the pressure side. You don't charge to that side, do you?
I'm going to test it this week to see if it will hold a vacuum.

 

[1 Wild R/T]

The picture below is during the mock up but it is how it looked when finished too. The #10 line off the firewall is in gas form since it is after the evaporator. It has the charge port in it like shown in the instructions.


View attachment 1631024

The high pressure side is over here:

View attachment 1631025

That is the pressure side. You don't charge to that side, do you?

No!! But you read the pressure as an indicator of state of charge...

 

[Kern Dog]

I thought that you connect the 3 hoses and that the system just follows whatever path that it is supposed to. All 3 hose ends are unique and cannot be attached to a wrong port.
I admit, I'm not familiar with this stuff.

 

[1 Wild R/T]

If you open the handle on the right (the red handle) you allow flow from the high pressure side to enter the tank... Generally the tank is big enough to absorb that but it still shouldn't be done... If you were to do that with one of the small 12oz cans it could explode... The only reason to open the red valve is during vacuuming & even then it isn't necessary... Just leave the red valve closed.... The gauges read the pressure in the system when the valves are closed or open..

 

[Chargerjase]

FYI, the reason you put the system in a vacuum is to remove moisture. The vacuum lowers the boiling point of water and the water actually boils off when doing this process.

 

[Kern Dog]

View attachment 1631026


If you open the handle on the right (the red handle) you allow flow from the high pressure side to enter the tank... Generally the tank is big enough to absorb that but it still shouldn't be done... If you were to do that with one of the small 12oz cans it could explode... The only reason to open the red valve is during vacuuming & even then it isn't necessary... Just leave the red valve closed.... The gauges read the pressure in the system when the valves are closed or open..

I've seen a few videos that also state to leave the red line and knob alone. I planned to put the vacuum pump on and see if it holds the recommended 30 in/hg or whatever the spec is.

FYI, the reason you put the system in a vacuum is to remove moisture. The vacuum lowers the boiling point of water and the water actually boils off when doing this process.

Thanks, I've heard that too. I am curious though....if the vacuum pump is pulling, where does the air inside go? The pump has no tank on it.

I have this thought of the A/C system being deflated like a water bottle but without collapsing. With that in play, whatever volume of air/Freon/compressor oil is in the lines has to go somewhere, right?

The unit has two fittings though. One connects to the yellow hose. Is the other port for an external tank?

 

[Kern Dog]

I just finished the installation of a Vintage Air system in a 68 Plymouth.

Vintage Air installation in a 1968 Satellite

Wednesday I am bringing the car to a local shop to do the evacuate and fill.
I may have them do the service on this car too but I want to find any leaks I might have before I take the car in.

 

[1 Wild R/T]

The air/freon is pumped out of of the system, the pump vents to the atmosphere... The oil remains in the system, if you were able to pull 30 in/hg water would boil at 90 degrees below zero... But since NASA didn't loan you their vacuum chamber you can't.. Hopefully you can get somewhere around 29.5 in/hg and at that point water boils at 53 degrees...

 

[Chargerjase]

The air/freon is pumped out of of the system, the pump vents to the atmosphere... The oil remains in the system, if you were able to pull 30 in/hg water would boil at 90 degrees below zero... But since NASA didn't loan you their vacuum chamber you can't.. Hopefully you can get somewhere around 29.5 in/hg and at that point water boils at 53 degrees...

Lol, that's exactly right. Sometimes it would be nice to have contacts at NASA, but for now a standard vacuum pump will do.

 

[Kern Dog]

Im out here in the shop with the vacuum pump humming away.

It has been going maybe 25 minutes. It went to 10 fairly fast but seems to be stuck here at 19 I’ll keep watch and hope it climbs. Failing to increase means a leak, I’m guessing. It couldn’t be crappy gauges or a defective vacuum pump from Harbor Freight!

I just spoke to a tech guy at CAA. He suggested that I check the heater control valve to see if it is stuck open. I wish I’d have called him first. I checked the pressure of this system a few weeks back and it read…

The gauge states that as low so I added some from a canister.

The air still blew warm.
Today the CAA guy said the heater control valve could be stuck open.
Son of a bitch. I wish that I’d called before hooking up the vacuum pump. Now it has sucked out whatever refrigerant was in there.

 

[Kern Dog]

I spoke with tech guys from both Classic Auto Air and Vintage Air today.
First, the CAA guy said that the warning to only charge/fill the system with the engine OFF only applies to those that are using a shop quality forced fill R-134 unit. Hobbyists using small canisters can fill either with the engine off or on. He did say that for the second canister, you’d need the engine running to draw in the rest since the canisters are not pressurized enough. The instructions are very clear to not charge with the engine running since the compressor will be damaged. This pissed me off. Why can’t they have just stated that in the instructions? I may have been chasing a dead end.
I told the Vintage Air guy that both they and CAA state to connect one heater hose to the “manifold” yet no BB Mopar has a water fitting there. He stated to put it nearest the thermostat. That helps. I guess every other engine has a “wet” manifold other than us.
I had the pump working for an hour now and it never went past 20. I shut it off and closed the blue knob/valve to see if it holds at 20 at all. It is holding but I’m an idiot with this.
Did turning this knob on the left:

…. just close off the gauge or the vacuum pump? Is it holding vacuum in the gauge while the system still could
have a leak?
I’m wondering if the system holds at 19/20 for awhile if it is actually airtight but the pump just couldn’t pull up to 30 like I wanted.

 

[Dennis H]

After Joe Sanderson (RIP) installed the CAA in the Coronet, I took it to a reputable AC specialty shop for a charge. 20 years ago. It’s still ice cold. At the time, only the original cable driven control box was available. Due to stretching, it always requires a tug at the firewall to ensure the hot water feed is entirely shut off. A small price to pay. I am totally ******* exhausted from all this reading. When I come across the red or blue car at a show somewhere this summer, they both better have ice cold ac. Jesus Chrysler.

 

[Kern Dog]

Yeah, I have a curious nature and try to do everything myself. Sometimes I end up spending more $$ in the process but it is either this or I sit on the couch, bored out of my mind while getting too fat to do anything.
I love solving a mystery.

 

[moparedtn]

After Joe Sanderson (RIP) installed the CAA in the Coronet, I took it to a reputable shop for a charge. 20 years ago. It’s still ice cold. At the time, only the original cable driven control box was available. Due to stretching, it always requires a tug at the firewall to ensure the hot water feed is entirely shut off. A small price to pay. I am totally ******* exhausted from all this reading. When I come across the red or blue car at a show somewhere this summer, they both better have ice cold ac. Jesus Chrysler.

Never one to mince words, that Dennis....