86 MkIII A/C charging help - Page 2

CyFi6 · 09-09-2008, 03:46 AM

Converting to R134a is a lot more than putting some fittings on and charging it. R12 uses mineral oil, which r134a doesnt transport very well, its not compatible. You have to get that old oil out before you can add new oil and refrigerant, and to do that you need to take your whole ac apart and flush everything out properly. Its a pretty big job. I reccomend you stick with r12. I did the whole conversion, put it tons of work and im not happy with it, i would have rather stuck with r12, its what the system was designed for.

batmmannn · 07-03-2010, 05:31 AM

Did my first AC evac and charge today. Went OK. My Ac is working. Should be interesting to see how long it lasts.

When I took off my compressor it had no oil. It was seized. Should I have assumed that the entire system would be dry or near dry of oil. I put about 4 ozs in the drier and the 4 in the compressor. I didn't want to go more in case there was a few ozs still in the condensor, lines and other parts of the system. Being that the compressor was bone dry should I have gone a full 10 ozs? My $9.99 AC compressor off ebay is working just fine and apparently not leaking.

Sight glass is not clear even after 3 cans of refrigerant. When the clutch disengages I see foam, when it reingages and is running I got a bubble or two about 180 psi on the high side and about 34 on the low side.

I did evacuate it down to -29psi and the vacuum held fine for like an hour and a half before I went forward and charged it. What do you guys think?

I didn't want to flush it. Besides I figured I would do this one and test for leaks. I used the same oil and refrigerant it had in it before I started on it. Put on a new drier, but man getting that thing bolted back in was a pain in the ass!

What were your results? Should I have added more oil or less?

Thanks

07-03-2010, 05:31 AM	#12
batmmannn 12psi boost Join Date: May 2010 Location: West Virginia Posts: 320	A/c Did my first AC evac and charge today. Went OK. My Ac is working. Should be interesting to see how long it lasts. When I took off my compressor it had no oil. It was seized. Should I have assumed that the entire system would be dry or near dry of oil. I put about 4 ozs in the drier and the 4 in the compressor. I didn't want to go more in case there was a few ozs still in the condensor, lines and other parts of the system. Being that the compressor was bone dry should I have gone a full 10 ozs? My $9.99 AC compressor off ebay is working just fine and apparently not leaking. Sight glass is not clear even after 3 cans of refrigerant. When the clutch disengages I see foam, when it reingages and is running I got a bubble or two about 180 psi on the high side and about 34 on the low side. I did evacuate it down to -29psi and the vacuum held fine for like an hour and a half before I went forward and charged it. What do you guys think? I didn't want to flush it. Besides I figured I would do this one and test for leaks. I used the same oil and refrigerant it had in it before I started on it. Put on a new drier, but man getting that thing bolted back in was a pain in the ass! What were your results? Should I have added more oil or less? Thanks __________________ 1987 N/A 7MGE Left Hand Drive MK3 Red 5 Speed and Black Auto Supras My Next project is the Batmobile! Last edited by batmmannn; 07-03-2010 at 05:47 AM.

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09-09-2008, 03:46 AM	#11
CyFi6 3" Exhaust Join Date: Oct 2007 Location: SLO Posts: 234	Converting to R134a is a lot more than putting some fittings on and charging it. R12 uses mineral oil, which r134a doesnt transport very well, its not compatible. You have to get that old oil out before you can add new oil and refrigerant, and to do that you need to take your whole ac apart and flush everything out properly. Its a pretty big job. I reccomend you stick with r12. I did the whole conversion, put it tons of work and im not happy with it, i would have rather stuck with r12, its what the system was designed for.