74-78 ATC II to Manual A/C Inspection (and conversion??)

[commando1]

A few years ago, I scored a manual a.c. heater box just to keep on the shelf just in case I ever decided to convert from ATC II in my 76 NYB.

Today, feeling ambitious, I cleaned off my workbench and dragged it down to open it up and inspect it. Took it apart, and I've sourced a new evaporator and heater core to start off with. This ain't gonna be cheap.

The disassembly of the MANUAL box for prosperity.

 

[traintech55]

With planning on converting the compressor, now is the time to do everything right. It may be expensive now, but you will be able to enjoy it for the next 10, 20 years, and if you break the price down like that it is down right cheap.

 

[commando1]

 

[commando1]

 

[commando1]

With planning on converting the compressor, now is the time to do everything right. It may be expensive now, but you will be able to enjoy it for the next 10, 20 years, and if you break the price down like that it is down right cheap.

You missed ny Sanden conversion thread. Already done.

 

[traintech55]

You missed ny Sanden conversion thread. Already done.

I stand corrected.

 

[Davea Lux]

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Most of the time the evaporators in these did not go bad unless there was a pile of mouse turds or some other corrosive element in contact with the core tubing. You can probably flush the core with nitrogen to remove any jellied oil and re-use it unless you just want it to be "all new"

Dave

 

[Polara_500]

So where does a fella get some of this nitrogen to flush with? I know the liquid stuff is kinda rough to work with..........

 

[Davea Lux]

So where does a fella get some of this nitrogen to flush with? I know the liquid stuff is kinda rough to work with..........

Any good welding supply has compressed nitrogen in cylinders. It is used to flush moisture out of new installations for natural gas or refrigerant system piping or to clean existing systems that have become contaminated somehow. I think it is also used in certain welding applications to provide a gas envelope around the arc.

Dave

 

[commando1]

That will save a ton of money. How do I test it after?

 

[78Brougham]

With planning on converting the compressor, now is the time to do everything right. It may be expensive now, but you will be able to enjoy it for the next 10, 20 years, and if you break the price down like that it is down right cheap.

Wait a minute... wasn't there another thread that just told us they're gonna stop making gasoline in the next few years? Lol

 

[1978 NYB]

Wait a minute... wasn't there another thread that just told us they're gonna stop making gasoline in the next few years? Lol

I'm not worried....I'm pretty sure there will be gasoline around for more than our lifetimes. LOL.

 

[1978 NYB]

That will save a ton of money. How do I test it after?

If I do mine.....which is a real possibility. I'm using a new evaporator and heater core. That is too much work to have a refurb part fail.

 

[live4theking]

You ambitious fella. You cannot blame the cost of this one on me.

 

[Davea Lux]

That will save a ton of money. How do I test it after?

That will save a ton of money. How do I test it after?

Probably the easiest way would be to take you existing system hose connections and attach them to the evaporator that you plan to install. I am assuming that you have a non-working ATC system that is still on the car. You can then hook up an evacuator to the system to see if it will hold vacuum. If the system holds vacuum, you know the evaporator is good. The problem with this method is that if the system has a leak someplace else, it will not hold vacuum. They used to make a test block that attached in place of the hoses to test just the evaporator, but given the age of these systems, it would probably be real hard to find one, maybe at a shop that has been in business a long time.

Dave

 

[Davea Lux]

That will save a ton of money. How do I test it after?

The other issue is are you planning to convert this system to R-134a or has that already been done? If you are going to do the conversion, go with a new evaporator. R-134a has a smaller gas molecule and therefore is much more prone to leaking. You will also need updated hoses and o-rings and you would also probably want to do the Sanden conversion as RV2 compressors do not do well most of the time with R-134a. A slight amount of undercharge on the system and the oil stops circulating and the compressor burns out and makes a big mess with metal shavings inside the system.

Dave

 

[barnfind]

 

[commando1]

You ambitious fella. You cannot blame the cost of this one on me.

Nope. Nobody but myself.

 

[commando1]

The other issue is are you planning to convert this system to R-134a or has that already been done? If you are going to do the conversion, go with a new evaporator. R-134a has a smaller gas molecule and therefore is much more prone to leaking. You will also need updated hoses and o-rings and you would also probably want to do the Sanden conversion as RV2 compressors do not do well most of the time with R-134a. A slight amount of undercharge on the system and the oil stops circulating and the compressor burns out and makes a big mess with metal shavings inside the system.

Dave

Like what was said above, I have done the Sanden conversion.
Everything new from cowl to bumper.

I am assuming that you have a non-working ATC system that is still on the car

No. I have an excellent, fully operational, functioning ATC II that blowshot to cold as it should.
And the spare electrical parts on the the shelf.
And an ATC II test box.

 

[Davea Lux]

Like what was said above, I have done the Sanden conversion.
Everything new from cowl to bumper.

In that case the worst is already done. You can hook the evaporator to your hose connector and evacuate the system. If it holds vacuum you should be ok. The question would come down to how comfortable you are with your used evaporator, if it shows no obvious signs of corrosion, I would put it in. But remember they are, as you are well aware, a major pain in the butt to change.

Dave