Hi guys,
I'm in the middle of detailing my engine compartment and would like to temporarily remove the AC unit. It doesn't work and I'd like it out of the way until I can renovate it.
Where is the best place to unhook it? I was thinking the POA valve but that joint won't budge and it looks aluminum and I fear I might destroy it. Any left-handed threads I need to be aware of?
I also haven't purged the system but I'm skeptical there's any refrigerant in it.

'71 Cutlass Supreme, bone stock, 350

 

Unless it has a MAJOR leak, I bet there is some pressure left in it. You can loosen one of the small fittings on the POA and drain out any pressure. Now that will release the refrigerant to the atmosphere and you will increase global warming by 10 or 20 times, and that is a bad, bad thing, so don't do it. If there is pressure in the system, that might make loosening the large fittings more difficult. I bought large flare crows foot wrenches which help greatly in loosening or properly tightening those large nuts

 

I doubt there is any refrigerant remaining in your system if it is 40+ years old. I removed the entire AC system from my 71 98 starting with the hoses, compressor and compressor bracket. I then removed both the condensor and the evaporator.

 

I have to side with Olds64 on this one. Considering the radiator hose was original and had four patches on it, I doubt anyone bothered to maintain the AC. Not to downplay the ozone, I want my child to have breathable air and the ability to go outside without getting radiation poisoning. Maybe I can crack it and if it starts hissing, close it back up?
Crows foot wrenches....got it.
I'm not looking to do a permanent delete, just while I do major work under the hood.
Thanks guys.

 

I would recommend removing the ENTIRE system - evap box, hoses, condenser and compressor.
Reason being is if you plan on restoring the AC later, then those parts would need to come out anyway.
This stuff will be in your way when doing your engine bay resto, and they will all need resto anyway.
I went through this so I know.

The condenser and evap will need to go to an AC shop to be flushed and pressure tested anyway.

Hoses will need to be rebuilt most likely.

I am sure the compressor brackets are dirty and removing the compressor helps expose them more. Compressor will need testing, rebuild, or at least the front seal replaced.

(Here comes the attack of the MAWs...)

Seal up the ends of all fittings with caps or even plastic wrap to keep dirt out.

--Use a small screwdriver to quickly depress the schradder valve on the POA or on the compressor rear manifold to see if it has pressure. My guess is it prolly doesn't.
The valve is just like a tire valve. Make sure to keep your fingers away in case it does have freon, as it will frostbite your skin on contact.

 

Is it still R12 or has it been converted to 134? Have you tried to add refrigerant to it? When I bought mine, the A/C didn't work. I was told it hadn't worked in 5 years but just needed a charge. Yeah, right I thought. But for the heck of it, I added a couple of cans and to my surprise, it worked fairly well. My point is it wasn't completely discharged and contaminated with moisture.

 

It's off and hoses are covered in saran and rubber bands (great minds, Rob). I checked the valve for pressure when I went back out to the shop (a real "duh" moment there). It hissed but it seemed pretty weak so I let it discharge. It hissed weakly for about three seconds and stopped. Maybe I shoulda' tried charging it (with a 134a conversion kit) before removing it but as brown said, I needed it out of the way anyway.
I degreased and painted the brackets, along with the power steering and alternator brackets.
Thanks for the help folks.
-Mac

 

Put an AC delete panel in place of the evaporator to cover the hole and keep heat functional. You will have a nice tidy engine bay while you decide if you want stock or aftermarket AC, or just stay with no AC.

 

Yeah Dane, I've been looking at those. Wife says she wants AC though, so the decision is made :-)

 

Macadoo, when you retrofit your system to R134a it might be worth it to look at an aftermarket system. I converted the system in my 90 Buick Estate wagon from R12 to R134a many years ago. It worked ok, but it never blew as cold as I would have liked. If I ever put AC back on my 71 98 I'm definitely going with an aftermarket system.

 

The only parts that will need attention for a 134 conversion is the hoses, compressor, POA/accumulator and condenser. The other parts will work fine for 134, but the evap should be flushed to remove oils.

 

Buy a crossflow condensor from Classic Auto Air. It is designed for 134A. My Cutlass with all OEM parts and a correctly calibrated POA and crossflw condensor blows 30 degree air and loses very little sitting in traffic. I live in south Florida and can use my car every day.

 

As far as hoses, you don't need new ones unless you old ones are shot or leak. "New" R 12 hoses will leak if you change to 134A. Old ones, if they are in good shape have had oil flowing through them and it seals them so 134 will not leak. Just change all the o rings and make sure there are no leaks. I have been running mine for over 2 years and have had no leaks.

 

Sorry guys, I've been busy with the engine. Thanks for all the information. AC is a bit down the road yet but at least I know what direction to go.