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Re: 1986 Corvette R-12 to R-134a Conversion

Posted: Tue Dec 20, 2022 3:15 pm
by tbirdtbird
yes. Pull from the low side only

Re: 1986 Corvette R-12 to R-134a Conversion

Posted: Tue Dec 20, 2022 5:08 pm
by kenlou
Well, I think I'm done with it until spring.
I pulled a vacuum from the low side only for one hour after injecting 4 oz of oil. Micron gauge showed 140 microns.
I used a digital weigh station and put in 25.6 oz of refrigerent and put the caps (they do have rubber gaskets) on both adapters.
I want to thank JohnHere and DetroitAC and tbirdtbird. Great bunch of guys :D

tbirdtbird, I used to live in Austin; if I still lved there I would definitely buy you a beer. I'll be back here in the spring to let you know how it all turned out

Re: 1986 Corvette R-12 to R-134a Conversion

Posted: Tue Dec 20, 2022 6:54 pm
by tbirdtbird
Good job. Good luck. Keep us posted. Have a nice Holiday
Texas Dave

Re: 1986 Corvette R-12 to R-134a Conversion

Posted: Fri Mar 31, 2023 8:07 pm
by kenlou
Hey Dave, I'm back. :lol: I will be ready here shortly to ask a few more questions concerning topping that corvette A/C off. I still need to add 11.4 oz of 134.

Re: 1986 Corvette R-12 to R-134a Conversion

Posted: Sun Apr 02, 2023 7:10 am
by kenlou
kenlou wrote: Fri Mar 31, 2023 8:07 pm Hey Dave, I'm back. :lol: I will be ready here shortly to ask a few more questions concerning topping that corvette A/C off. I still need to add 11.4 oz of 134.
The car has been sitting all winter with the holding charge of 25.6 oz of r134a. How exactly do I connect the gauges to check the current status? And what do I do to add the remaining 11 oz of refrigerant?
I have left the A/C compressor wire disconnected and I finally connected the wire back on to the A/C compressor. I started the car to do other work to it and noticed that the compressor clutch did not engage when I turned the AC on. Should it have started?

Re: 1986 Corvette R-12 to R-134a Conversion

Posted: Sun Apr 02, 2023 10:02 am
by JohnHere
Hard to tell whether there's enough refrigerant in the system to run the compressor.

If it were mine, I would start from scratch: recover/evacuate/recharge. On recovery, the RRR machine will show how much it recovered. You can then compare the recovered amount to your original holding charge of 25.6 ounces. If there's a significant difference, then you'll need to find the leak, repair it, and evacuate/recharge again.

Or, you could take a chance and presume none leaked out over the winter, add the remaining charge of 11 ounces by weight, and performance-test the system. If the compressor runs but the vent temperatures and pressures are off, then you'll know that at least some refrigerant leaked out during the winter, and you'll need to find the leak, evacuate, and recharge.

Re: 1986 Corvette R-12 to R-134a Conversion

Posted: Sun Apr 02, 2023 7:26 pm
by tbirdtbird
Agree

Re: 1986 Corvette R-12 to R-134a Conversion

Posted: Sun Apr 02, 2023 8:56 pm
by kenlou
Ok, I will do that, but I would like to add the remaking first and see exactly what is working here and what isn’t. Once I get the remainig charge in, I will get it evacuated and will compare what comes out vs what I charged.
What is the procedure for me to get the remaking charge in at this point?

Re: 1986 Corvette R-12 to R-134a Conversion

Posted: Mon Apr 03, 2023 7:11 am
by tbirdtbird
You would ideally weigh it in, barring that, put in an entire 12 oz can. The reason this will be OK is that you can never get all 12 oz out, just put in as much of the can as possible.

As far as the comp not coming on before, it usually will not if undercharged. And if it does, it won't cool at all

Re: 1986 Corvette R-12 to R-134a Conversion

Posted: Mon Apr 03, 2023 7:31 am
by kenlou
I will weigh in the remaining 11 oz. Do I add as a liquid on the low side?