A/C suggestions - keep OEM setup or go classic?

[tommyg29]

The scoop is I have a '72 400-4 runner with a non-working factory a/c system. Dont know yet what the issue is, but regardless, I have heard it can be a PITA to keep these old systems working well, especially where they will be used and relied on a lot. If its going to cost a lot to get it working, and then more $ to keep it running, maybe I should just update the whole system? I live in Florida, so Classic air is only a 4 hour drive away for me.

Also, I want to convert to an air grabber. I would just shelve the original system and store it, and go with a hidden sanden (under the alternator), but I have heard the hidden compressor bracket wont fit with a mechanical fuel pump, and isnt recommended for full time use, whatever that means.
Can anyone convince me to stick with the factory system?
Thanks.

 

[snakeoil24]

Stay with oem and update with new compressor, drier condenser. Then have your evaporator rebuilt by Glen ray. The new compressor "rotary is very efficient and the factory housing fits the car with no crap! You will need to replace valves and expansion tank for r134. A good guy to deal with is Bouchillion performance.

 

[Dennis H]

If going with the hidden compressor, I'd go with new components. When touring Classic, they were working on many Power-Tour cars and that was years ago. You would not hide the compressor and keep other stock components right?

 

[ODZKing]

If mine were working and all there when I purchased the car, I would have simply done the conversion over to the new refrigerant.
Since I was missing hoses and some pieces I decided to go with the Classic Auto Air conversion.
It works but lets just say there are issues with it. Freezes constantly is the biggest.
I would have stayed with the original system ... but it's done now.
So my 2 cents???? Fix what is there and keep it. Do the change over to the new refrigerant, but keep the original parts.

 

[5.7 hemi]

The factory ac compressor can not be used with an air grabber set up. So switch to a Sanden 508 compressor, or go with a low mount compressor that installs under the alternator (Bouchillon).

 

[Dennis H]

Mine shows 23 f at the vent and has never "frozen. I keep hearing this with no explanation or fix.

 

[tommyg29]

Thanks given to everyone!
Consensus is the factory system is the way to go especially if I want to keep the car original as possible, but then I give up my dream of an air grabber.
I will wait until I get a chance to really go over the whole system. If EVERYTHING is crap, I may just go classic.

 

[A383Wing]

Stay away from Classic...I got one over here that does not work very well and their help department is worthless.

You do not have to change any valves if you go with 134a....a new receiver drier would be needed, but that is all

 

[idrivemopar]

I went with classic, they rebuilt my rv2 compressor. Got new condensor and receiver/dryer and had my hoses done for 134. It was expensive and their support has been great. Only issue with the setup was their thermal cut off switch was not very good but I found one that is adjustable and works well preventing freeze up.

 

[ODZKing]

I went with classic, they rebuilt my rv2 compressor. Got new condenser and receiver/dryer and had my hoses done for 134. It was expensive and their support has been great. Only issue with the setup was their thermal cut off switch was not very good but I found one that is adjustable and works well preventing freeze up.

Which cut off did you purchase (not that I should have to) to make it work right?

 

[Dennis H]

Which cut off did you purchase (not that I should have to) to make it work right?

Explain freeze up. Only issue ever with Classic was condensation on passenger floor. Ran a hangar in the firewall drain, and it was resolved.

 

[idrivemopar]

Which cut off did you purchase (not that I should have to) to make it work right?

So, if you have converted to 134a, you need an external cut off switch I am told because the EPR valve is removed on the compressor in conversion type setups. So this type with capillary that you lay over the low pressure hose, typically next to where the expansion valve capillary goes. The one from classic broke, part of the housing separated mis-aligning it so it would never cut off. I found the Murray 35720 at Oreilly, for only 17 bucks, much less expensive than the one from Classic, and a better built part.

Here is what it looks like, which is actually different than their standard picture on the web site. It also has cut in and cut out adjustments on it, if needed, but comes set to freezing.


Here is where I attached the capillary, using some heat tape to secure it to the pipe.


I installed mine in the cowl area, because putting on the fire wall it just gets too hot, and that may have led to the other one failing because it sat just above my headers.

 

[ODZKing]

Everything you said, completely correct. However, everyone has told me that in order for it to work "properly" it should have gone into the heater box on the evaporator which is what freezes up. Putting it on the outside is not the correct way to do it because heat from the engine gives it an incorrect reading.
But I see you remedied that issue by putting it on the other side in the cowl vent area. I actually thought of that but wasn't sure it would work.
Another fellow suggested getting a variable switch. The CAA system works pretty well when it doesn't freeze. And turning it on and off every few minutes gets tiresome on a long trip. Maybe I'll try that and see if I have any luck with the existing switch.

 

[Dennis H]

Everyone here knows more than I. Does this cause less cycling of the clutch? Why has the problem not surfaced with 23f at the vent. Is it common when switching from R12 to 135. The clutch seems to cycle often, don't know what is normal. Only reason I am here is because. i don't want it too quit.

 

[ODZKing]

I learned most of this myself when installing my conversion. As IDrive stated, you need an external cut off switch, because the EPR valve is removed on the compressor in conversion type setups. So as is pictured in mine, you lay the sensor over the low pressure hose, typically next to where the expansion valve capillary goes. But the problem is no matter how much insulating material you put over the sensor, the heat from the engine warms it so it would never cut off. That is the problem I am having.
The old compressor had it built in, these are not therefore you need a separate thermostat basically. But it should be in the heater box next to the evaporator which is what freezes. Instead they give you this contraption which doesn't work properly.
so yes, it is supposed to cut on and off to keep the evaporator from freezing. But when you say "a lot" what do you mean?

 

[Dennis H]

Thanks. Clutch makes a distinctive click when engaging. Could be more than one time per 60 seconds, not sure. Will time it.

 

[idrivemopar]

Hey ODZKing, I see you placed your switch almost exactly where I had mine, and why it failed. Also, I have wrapped the capillary and section of pipe with reflective heat tape, then used a section of pipe insulation so it looks like this.



I was getting some condensation and frost on the pipe and even up to the compressor with this setup, so seems its insulated enough to prevent the heat from having too much impact on the switch working properly, however, I think I have a slow leak some where, as I have been testing, the system is not getting as cold as it was when I first charged it, so back to checking pressures and trying to find the leak.

I also noticed that your low pressure pipe seems to have a different configuration.

 

[ODZKing]

Mine is a 73 Charger and had factory A/C. When purchased it was missing most of everything under the hood, so all I did was convert everything as per CAA.
That is what they sent.
Yours does look much different ... different year? B Body?

 

[idrivemopar]

Mine is 73 Roadrunner, small block. Fire wall should be nearly identical. also, the high and low pressure hoses are original to my car, just upgraded to handle 134a. I am running the RV2 compressor, are you using a different compressor then?

 

[ODZKing]

Ahh, my hoses came from CAA, orig ones were gone when I got the car.