Freon Capacity
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by bmankin
I can not find the original freon capacity on a 1977 with a R4 compressor. Can anyone help?
Call a shop or a dealership service center. Shops that can do an AC flush and fill have to be able to look it up. They will probably be able to look it up for you.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by chevylit
In the specs section of My 77 Owners manual it shows 11oz of compressor oil and 3 lbs of R12. Ah yes,the good old days when R12
was available everywhere for 99 cents a lb.
was available everywhere for 99 cents a lb.
It's what now? $12 a lb for 134?
Burning Brakes
Joined: Sep 2005
Posts: 1,044
Likes: 33
R-12 is still around and I would not change it over unless you have leak issues. The system in you car is set up to work with R-12 and converting it over causes contamination issues and heat tranfer issues because R-134 needs a larger condensor and more refrigerant to work properly and yours is made for R-12, AL.
Thread Starter
Advanced
Joined: Sep 2004
Posts: 87
Likes: 0
From: TN
Originally Posted by IDOXLR8
R-12 is still around and I would not change it over unless you have leak issues. The system in you car is set up to work with R-12 and converting it over causes contamination issues and heat tranfer issues because R-134 needs a larger condensor and more refrigerant to work properly and yours is made for R-12, AL.
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Burning Brakes
Joined: Sep 2005
Posts: 1,044
Likes: 33
Originally Posted by bmankin
I had to get a new compressor,hoses and drier so I went ahead and converted to 134A. I've got an electric fan installed also so I'm hoping that will help.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
The other thing to consider when changing to 134 is this. A 134 system cannot have flaws ot it loses up to 40% efficiency. You have to completely flush and clean the system, probably a shop would be best suited for this.
You have to replace the drier with a new, larger unit...not hard.
And you have to make sure the radiator and condensor have no bent fins and no blockages.
With a good designed 134 system, good airflow, with no trash is the system, you can have 40 degree air. I've seen in done in a converted '57 Chevy. Froze my ***** off.
You have to replace the drier with a new, larger unit...not hard.
And you have to make sure the radiator and condensor have no bent fins and no blockages.
With a good designed 134 system, good airflow, with no trash is the system, you can have 40 degree air. I've seen in done in a converted '57 Chevy. Froze my ***** off.
Burning Brakes
Joined: Sep 2005
Posts: 1,044
Likes: 33
Originally Posted by IDOXLR8
I've seen many change overs go well but its R-12 for me. When you changed your system over did you go to a different Orifice/screen or use the same one that would have been used with R-12? AL.
Thread Starter
Advanced
Joined: Sep 2004
Posts: 87
Likes: 0
From: TN
Originally Posted by IDOXLR8
I've seen many change overs go well but its R-12 for me. When you changed your system over did you go to a different Orifice/screen or use the same one that would have been used with R-12? AL.
Burning Brakes
Joined: Sep 2005
Posts: 1,044
Likes: 33
Originally Posted by bmankin
I did change the orifice/screen. I'm close to the end of a complete restoration so I had every AC component out of the vehicle. It was setting with a zero R12 charge so it just seemed like the thing to do. I have access to gauges vacuum pump, recovery machine and any thing else that might be used. I'm a little nervous about the outcome, but worse case scenario I can take it back to R12 without to big of an ordeal. That is if the oil I used is backwards compatible with R12
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by IDOXLR8
not to mention that the goverment has announced that the R-134a has globle warming potential and is slated to be dropped like R-12.
Yikes...do they have a cleaner refrigerent to use when that happens?
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by IDOXLR8
The R-12 deal all over again with R-134a 
, AL.
, AL.They'll figure it out...they always do. Maybe expensive to change, but with todays chemical technology being what it is it should be very efficient.
Team Owner
Joined: Oct 2004
Posts: 23,831
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From: Springfield MO
St. Jude Donor '07
I think there is a mineral oil that is compatible with 12 and 134a. Who knows what they're gonna come up with next, but I need to take my A/C apart, so I'm going to go ahead and switch to 134a (but I'm going to get my 609 certification just in case). Dang scientists...just invent a non-polluting, non-flammable refrigerant once and for all and get it over with.