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Discussion Starter #1
I changed my A/c compressor back in 2016 after it started to smoke while sitting idle for a while on a hot day. I replaced it with UAC compressor. Last year one or two times the a/c would stop blowing cold at idle again as the clutch would seize up but I turned it off before any smoke occurred.

From last year up until this summer it has been working just fine and is cold even when idle for a while.

Today was 99 degrees in NYC and I started the vehicle and left the a/c on to cool the interior. I saw smoke coming out the hood from inside my house and ran out to turn the a/c off. I opened the hood and saw the clutch was sticking.

After I started driving the compressor is working perfectly fine again and have no trouble on a 30 min trip going and coming back home.

I have no a/c leaks and system reads fully charged.
 

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When you replaced the compressor, did the new unit also included a new clutch? If not, the old clutch may seizing up intermittently.
 

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Since you have a history of this problem going back to 2016, then here's what might be the cause. The clutch is burning up due to slipping of the clutch on the belt and overheating the clutch and melting the rubber. The reason it is slipping is that the compressor is locking up at the higher RPMs. You may need to reclaim the A/C refrigerant and disconnect an A/C line to see if there is black or dark grey residue in the system. This is due to the desiccant in the receiver/drier coming apart and clogging the entire A/C system. Another possible cause could be due to an overcharged system.
 

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Discussion Starter #5
Since you have a history of this problem going back to 2016, then here's what might be the cause. The clutch is burning up due to slipping of the clutch on the belt and overheating the clutch and melting the rubber. The reason it is slipping is that the compressor is locking up at the higher RPMs. You may need to reclaim the A/C refrigerant and disconnect an A/C line to see if there is black or dark grey residue in the system. This is due to the desiccant in the receiver/drier coming apart and clogging the entire A/C system. Another possible cause could be due to an overcharged system.
The clutch actually locks up when sitting at idle for a while. And Ive noticed it happens on extremely hot days. That is what happened to the original compressor a few years ago. And same thing with this aftermarket compressor, once last summer and once this summer so far. When I accelerated the vehicle, the clutch started spinning again.

Right now its working fine again, but a bit noisy after seizing up while on and started smoking a bit. I shut it off as soon as I saw the smoke.
 

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Sup Mod keeping the peace
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Well sooner or later you'll have to fix the problem unless you want to keep buying replacement compressors.
The general "rule-of-thumb" when replacing the AC compressor is that the AC receiver/dryer should be replaced any time your AC system is opened for service; actually the entire AC system must be flushed and the consumables and non-flushable components must be replaced when the compressor is replaced!
 

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My new compressor came with expansion valve and condition system be flushed to activate the warranty. maybe liquid is geting to low side causing hydraulic lock and clutch to slip and burn up.
 

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Discussion Starter #8
Well sooner or later you'll have to fix the problem unless you want to keep buying replacement compressors.
The general "rule-of-thumb" when replacing the AC compressor is that the AC receiver/dryer should be replaced any time your AC system is opened for service; actually the entire AC system must be flushed and the consumables and non-flushable components must be replaced when the compressor is replaced!
I believe the receiver/dryer was not changed by mechanic at that time. I am going to change this out myself along with compressor and expansion valve. Then have system vacuumed and recharged by mechanic.

The compressor kit comes with pag compressor oil. Where do I add this and how much? I am using a UAC compressor.

thank you
 

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The oil is distributed around the system. normally you measure the amount in old compressor and put the same amount in the new compressor and then install it. Too much oil will cause the compressor to lock and potentially damage it.
 

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Discussion Starter #10
When changing the compressor, can I remove it without evacuating the system? And catch what drips into a container just by opening the lines from compressor?

I am changing the system out on my own then having it vacuumed and recharged by my mechanic. Many mechanics want over $200 to change the components, so I am going to tackle this myself.
 

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When changing the compressor, can I remove it without evacuating the system? And catch what drips into a container just by opening the lines from compressor?

I am changing the system out on my own then having it vacuumed and recharged by my mechanic. Many mechanics want over $200 to change the components, so I am going to tackle this myself.
When you replace the compressor, you will lose the refrigerant because you're opening up the system. The refrigerant will escape as a vapor; nothing to catch.

I believe the receiver/dryer was not changed by mechanic at that time. I am going to change this out myself along with compressor and expansion valve. Then have system vacuumed and recharged by mechanic.
The compressor kit comes with pag compressor oil. Where do I add this and how much? I am using a UAC compressor.
Most replacement compressors come with PAG oil pre-installed. You'll have to read the instructions. If the instructions say to add PAG oil, then pour the oil very slowly into the intake port or low side of the compressor. This is where the large line connects. While pouring in the refrigerant oil, rotate the hub and clutch slowly to let the oil enter the compressor. If the compressor takes 6 oz. of oil per the instructions, use all 6 oz. Once that is completed, lay the compressor down on the hub for about 10 minutes to let the oil seep into and lubricate the front seals to prevent leaks on startup.
 

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Discussion Starter #12
When you replace the compressor, you will lose the refrigerant because you're opening up the system. The refrigerant will escape as a vapor; nothing to catch.


Most replacement compressors come with PAG oil pre-installed. You'll have to read the instructions. If the instructions say to add PAG oil, then pour the oil very slowly into the intake port or low side of the compressor. This is where the large line connects. While pouring in the refrigerant oil, rotate the hub and clutch slowly to let the oil enter the compressor. If the compressor takes 6 oz. of oil per the instructions, use all 6 oz. Once that is completed, lay the compressor down on the hub for about 10 minutes to let the oil seep into and lubricate the front seals to prevent leaks on startup.
Yes I checked this compressor I purchased came with the PAG oil filled already.

So if I do not have evacuation tools, I can still simply remove the compressor and the refrigerant will be evacuated as vapor? Just want to make sure I can open system with refrigerant inside.

thanks again
 

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Yes, you can open the system but be very careful and slowly disconnect the low side to the compressor first because the system may still be under pressure.
 

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The sysrem will be under pressure till all Freon is gone. do this slowly, wear gloves and eye protection.
You casually say it has Oil installed. how much oil ? does it assume a dry system with no oil in evaporator and condenser?
I had this same issue and had too much oil in the system.
 

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Discussion Starter #15
The sysrem will be under pressure till all Freon is gone. do this slowly, wear gloves and eye protection.
You casually say it has Oil installed. how much oil ? does it assume a dry system with no oil in evaporator and condenser?
I had this same issue and had too much oil in the system.
Came with 6.5 oz of oil inside compressor.
 

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Looks like you're all set to go. Make sure to use new O-rings at the compressor.
 

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great, out of interest and to help others did it say the 6.5 oz was for a in use system or new dry system. I have read to reduce the oil for in use system by an oz or two for evaporator and condenser.
 

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Discussion Starter #19
great, out of interest and to help others did it say the 6.5 oz was for a in use system or new dry system. I have read to reduce the oil for in use system by an oz or two for evaporator and condenser.
No, it did not specifically say for an I use or dry system. Just had a yellow tape around stating the compressor is filled with 6.5oz of PAG oil.

However, I had the system vacuumed and charged by my Nissan mechanic. And he verified the correct amount of oil and proceeded.

Everything has been working great so far and A/C is very cold.

One point to note is to use factory o rings around the receiver/dryer. It tends to leak there when the aftermarket rings are used. However, no trouble when aftermarket rings are used on the compressor lines itself.
 
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