Need some a/c help here guys

CuttyTee

Not-quite-so-new-guy
Feb 1, 2022
14
3
So I have a beautiful 1988 cutlass supreme with a gen3 4.8. I just did the AC and kept it all original to the car, except for used a pancake r4 compressor from a 94 c1500 instead of r4 from cutlass because it uses a 6 rib clutch for the ls. Replaced Orifice cleaned all the lines replaced the accumulator,Cleaned out Evap and condenser. Primed system with oil pulled 30 in of vacuum for 30 min. Held that vacuum for hours. Charged ac and compressor got really hot, smoked brand new compressor. Metal in orifice. So I Just replaced everything AGAIN including compressor, orifice ect. everything went fine again and yet again instantly smoked my brand new @&$@?!! compressor😑😑 I’ve been a professional mechanic in southern Arizona for over 8 years. I’ve done HUNDREDS of ac systems and have never had a issue besides maybe missing a bad seal and not holding vacuum. Go to do my own on my beautiful pride and joy. Alll the problems 😂 I really need some help here. I had some ac bracket alignment issues originally. I had to shorten all the spacers for the AC bracket 3.15 mm to get the belt lined up correctly. I got it within thousands. Not sure if a VERRY very slight misalignment of the ac would smoke the compressor? The belt tracks good and I’ve drove it for days without compressor Engaged, no issues with belt or alignment and the ac clutch pulley doesn’t get any hotter than the Idler pulley so no issues there. Only when I try to engage it’s not happy. Pretty sure my Orifice is filled with metal again I’m afraid to look.
 

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ELCAM

G-Body Guru
Jun 19, 2021
564
93
How many ounces of oil are you using? Where are you putting it? What kind of oil?
 

CuttyTee

Not-quite-so-new-guy
Thread starter
Feb 1, 2022
14
3
How many ounces of oil are you using? Where are you putting it? What kind of oil?
I used pag 150 both times. Put 2 Oz in low side line, 3 Oz in compressor. Spun with spaner wrench 20 times, quick engaged compressor 10 times for good measure after vacuum was pulled and and a can of Freon was put in
 

CuttyTee

Not-quite-so-new-guy
Thread starter
Feb 1, 2022
14
3

Supposed to be an 8 ounce system.

Also see this:

"Chick" has been working on A/C since these cars were new he knows of what he speaks.
I know it’s supposed to be eight Oz of mineral oil for the original r12 but it’s been converted. 134 a should need a little less than r12 as the amount of 134a required in the system will be less than the amount of r12 required originally. I went 6 Oz total the first time and a little less the second. I will try more oil tho and see if that makes a difference. Appreciate the info
 

airboatgreg

Comic Book Super Hero
Oct 2, 2016
2,661
113
Do not put oil in the low side line. That puts it directly in the compressor. Put the oil in the accumulator. Rule of thumb on a DRY system is 3 oz in the evaporator, 3 in the condenser and 4 in the accumulator. As you did drain the oil out of the new compressor and spin by hand. I would also recommend that you keep it on the vacuum pump at least an hour. More is better. Just because the vacuum pump reads 30 inches of vacuum does not mean it is working to boil out the moisture. Take a small glass bottle and solder an AC fitting on the lid. Put about an ounce or so of water and a few drops of AC oil in it. Tighten the lid and put the vacuum pump on it. If the pump is working properly the water will boil. When was the last time you changed the oil in the vacuum pump? The oil holds a lot of the moisture the boils out of the AC system. I have never seen an air operated vacuum pump boil water. DM me if you want to discuss more
 
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CuttyTee

Not-quite-so-new-guy
Thread starter
Feb 1, 2022
14
3
Do not put oil in the low side line. That puts it directly in the compressor. Put the oil in the accumulator. Rule of thumb on a DRY system is 3 oz in the evaporator, 3 in the condenser and 4 in the accumulator. As you did drain the oil out of the new compressor and spin by hand. I would also recommend that you keep it on the vacuum pump at least an hour. More is better. Just because the vacuum pump reads 30 inches of vacuum does not mean it is working to boil out the moisture. Take a small glass bottle and solder an AC fitting on the lid. Put about an ounce or so of water and a few drops of AC oil in it. Tighten the lid and put the vacuum pump on it. If the pump is working properly the water will boil. When was the last time you changed the oil in the vacuum pump? The oil holds a lot of the moisture the boils out of the AC system. I have never seen an air operated vacuum pump boil water. DM me if you want to discuss more
put it low side before the accumulator bud👍Good to go there. I did about 40 min of vacuum but 30 has always been plenty for me here in dry souther az, unless it’s crazy monsoons or something. It also held 28 inches over night last night. Before I pulled the vac last night I checked My orifice and it was clean, blew the condenser and hi side line out from the compressor to the orifice also clean,(yesss) added more oil and sealed it up. 8 Oz in system now. I will definitely try more vacuum time tho what the hell. Ha My vacuum pump works well, just did a system with it last week no issues. Today I had to pulled the dash in my truck that’s also getting a new ac system so vacuum pump will be tested again tomorrow. Then once that’s done back to my car and I will give a fresh update. Thanks for the advice much appreciated (yay dash work) lol
 

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CuttyTee

Not-quite-so-new-guy
Thread starter
Feb 1, 2022
14
3
Do not put oil in the low side line. That puts it directly in the compressor. Put the oil in the accumulator. Rule of thumb on a DRY system is 3 oz in the evaporator, 3 in the condenser and 4 in the accumulator. As you did drain the oil out of the new compressor and spin by hand. I would also recommend that you keep it on the vacuum pump at least an hour. More is better. Just because the vacuum pump reads 30 inches of vacuum does not mean it is working to boil out the moisture. Take a small glass bottle and solder an AC fitting on the lid. Put about an ounce or so of water and a few drops of AC oil in it. Tighten the lid and put the vacuum pump on it. If the pump is working properly the water will boil. When was the last time you changed the oil in the vacuum pump? The oil holds a lot of the moisture the boils out of the AC system. I have never seen an air operated vacuum pump boil water. DM me if you want to discuss more
And definitely not a vacuum pump you hook to an air compressor. It’s a 4CFM rotary vein vacuum pump for a/c. 110v
 
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69hurstolds

Geezer
Supporting Member
Jan 2, 2006
6,633
113
Just 1 can of refrigerant? 12 ounces? That's enough from empty to allow the pressure switch to cycle? Hmm. I was always under the impression that you would need about 1/2 a charge before the switch would cycle worth a flip. My mind may be off here, but it's what, 3.25 pounds of R12 (52 oz) for a normal G-body charge, thus at 85% you're looking at 44 oz of 134a. And a 12 oz can is about 1/4 of a charge. That just doesn't seem like enough. I haven't done a conversion in 600 years, so my memory ain't so good on that. You're not slugging liquid refrigerant in there when the compressor is engaged are you? If you do, it's Russian roulette for your compressor.

Maybe I'm missing something here. But it seems your oil amount is correct (now). The refrigerant is only going to carry whatever oil the refrigerant is going to carry. A tad more oil shouldn't hurt it. But not enough may. Good luck with this.
 

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