i'm in the same situation as you. i think my original comp is good but there was no freon in it when i got the car.
AC questions
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Race Director
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From: Out Where the Buses Don't Run, Eglin AFB/ Niceville FL
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AC questions
The air conditioning in my 82 does not work. I replaced the contol unit in the centre console due to the levers being broken. That part works and I can go to AC and get air through the vents. The compressor does not come on. The car sat for a number of years and I suspect the compressor is empty. Should it try to come on if empty? I'm trying to determine if the compressor is bad before I try to recharge it.
Since R12 is getting harder to find and even harder to get someone to service, should I go ahead and convert the system to R134? Could I keep the original compressor if it's good? Will buying the kit minus the compressor be OK? I plan to sell the car locally and selling a car with no AC in Florida is near impossible.
Since R12 is getting harder to find and even harder to get someone to service, should I go ahead and convert the system to R134? Could I keep the original compressor if it's good? Will buying the kit minus the compressor be OK? I plan to sell the car locally and selling a car with no AC in Florida is near impossible.
Melting Slicks
Joined: Jun 2009
Posts: 2,709
Likes: 3
From: Savannah GA
Not quite... if the low pressure switch is disabled the compressor will run if the clutch works and the unit is not seized. This is no guarantee the compressor does not leak. The only way to be certain the whole system is OK is to put some charge in it and look for leaks using either a sniffer, or a dye. R134 conversion kits are pretty cheap... certainly worth investing in even just to troubleshoot... and a converted system is a good selling point for the next owner.
Race Director
Joined: Sep 2001
Posts: 10,560
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From: Wellington, FL
St. Jude Donor '11 thru '25
To test for leaks, you can add a can of 134a instead of r12 as it's a little cheaper. Just be sure to remove it before fully charging with r12. I personally would stay with r12 as it will cool better than 134a. It is still widely available on Ebay for $25 a can or so. Good luck.
Advanced
Joined: Mar 2010
Posts: 66
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From: Phoenix AZ
I just picked up my 78 and it had been sitting in a garage in Michigan for 12 years with only 1000 miles put on. I saw the last oil change sticker on the door dated 1998!! So I had the same issue with the air and it turned out to be a frozen ac compressor. I had that replaced and also changed the dryer and all hoses. I had to convert it to 134R. Needless to say, with all the 110 days here in Phoenix, it is still running warm. It does work, but not well.
Melting Slicks
Joined: Mar 2008
Posts: 2,023
Likes: 6
From: Austin Tx
I'm using r134, and live in Texas - 102 today and had 54 degrees at the vent. Also, other than the conversion to r134, my system is stock. I think one of the things that can really help a system running r134, is to use a very good oil.
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Pro
Joined: Jul 2004
Posts: 605
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From: Alta Loma CA
The only way R134 will cool well is with a new cross flow condensor. I made my '73 system like an '82 setup with R134 a new condensor and a Sanden compressor. I get 42 degrees out of it.
You can't go back and forth between the two types of freon. You must flush the entire system clean. Also 134 uses a different type of oil in the compressor.
You can search my old posts to read more of how I set this up.
Check the forum on a/ckits if you want to get major a/c info. That's where I got my condensor. I can't remember who but Vintage Air or someone like them has a condensor kit available. I got my compressor on Ebay and brackets from Alan Grove. Had a local a/c shop make cutom hoses.
You can't go back and forth between the two types of freon. You must flush the entire system clean. Also 134 uses a different type of oil in the compressor.
You can search my old posts to read more of how I set this up.
Check the forum on a/ckits if you want to get major a/c info. That's where I got my condensor. I can't remember who but Vintage Air or someone like them has a condensor kit available. I got my compressor on Ebay and brackets from Alan Grove. Had a local a/c shop make cutom hoses.
Race Director
Joined: Apr 1999
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From: CORVETTE 77 385 C.I. TEXAS
For R134, I would use a smaller orifice tube like the Ford (2 O-Rings) Red .062 in place of the GM White .072.
Pro
Joined: Jul 2004
Posts: 605
Likes: 0
From: Alta Loma CA
I did not change the tube. Many others have recommended that change. But I had mine cooling where I wanted it before I ever read that suggestion. So I did not do it, I didn't want to do another recharge. But works great without that change.
Racer
Joined: Sep 2009
Posts: 437
Likes: 3
From: Alvin Texas
R134a A/C experience.
I had to replace my compressor on my '82 this summer, also replaced the accumulator and orifice (stock). I flushed the condenser several times with a/c flush agent both ways until it came out clean. There was a lot of trash in it. I evacuated it for 2 hrs (probably an over kill in most opinions, but this the TX gulf coast) then charged with 6 oz PAG 150 and about 24 oz of R134a. With a fan blowing through the condenser and the clutch cycling switch bypassed. I charged to get the 24-25# on low side the high was 190# @ at an ambient temp of 95+. Then readjusted the cycle switch to cycle at 25#. Yesterday, ambient temp was 101* the outlet temp 48*-50*.