AC compressor oil capacity?

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1low4x4

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Hey guys Im getting ready to install this ac compressor. I cant ever remember how much oil to put in. It came charged with 3oz. of oil. Its the pancake style. Truck in my sig.

Also, what hole do I pour it in again?
 

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1low4x4

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Free website I found also, but 10 ounces sounds like too much
 

bucket

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I always put two ounces in the suction port and then rotate the compressor by hand several times.
 

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I always put two ounces in the suction port and then rotate the compressor by hand several times.

When you say rotate by hand, do you do it with the clutch engaged? (12v jumped)
 

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When you say rotate by hand, do you do it with the clutch engaged? (12v jumped)

I just grab the face of the clutch to turn it. Some are a little too tight to do that easily with, so I just carefully set it down in a vice. Just lightly clamp the jaws on the edge of the clutch plate, then spin the compressor body itself.
 

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I thought these things came pre-oiled, and the refrigerant came mixed with PAG oil. Do you always have to add to the compressor?
 

smoothandlow84

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They usually come pre oiled. Per the instructions on my new ac compressor, it directed me to add 2 ounces of pag oil prior to installation.
 

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They didn't used to always come with oil, but I've been out of the game for a few years now. When they did come with oil, I always dumped it out and started fresh. Occasionally you get one that has way too much put in it.
 

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Im afraid I should've poured the oil out and started over. I added 5oz to the 3 the compressor said it had, and it cools, but no bite to the air. The gauges read perfect, we put in the 3 cans of refrigerant like we always do. Im afraid I may have too much oil
 

chengny

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Im afraid I should've poured the oil out and started over. I added 5oz to the 3 the compressor said it had, and it cools, but no bite to the air. The gauges read perfect, we put in the 3 cans of refrigerant like we always do. Im afraid I may have too much oil

The oil in a automotive AC system doesn't stay where you add it. It becomes entrained in the refrigerant and travels around the the entire system. GM specs the quantity of oil to be added to a purged system as below:

•Compressor- (1 ounce)
•Evaporator - (3 ounces)
•Condenser - (1 ounce)
•Accumulator (2 ounces)

When an R-12 system is retrofitted to 134a, the general rule of thumb is that the refrigerant capacity/charge should be reduced to 80-90 % of the original capacity.

The original GM spec for these trucks was 56 ounces of R-12. So, if we take 56 ounces of R-12 and multiply it by .85, we get a 134a charge of 48 ounces.

I always use 4 standard 12 oz (1 lb) cans.

To cause a noticeable loss of cooling capacity - by adding too much oil - you would have to add way more than you did. Try another can of gas...
 

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Thanks chengny
 

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I found this relating to A/C conversions on You Tube. They use a 91 K5.

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imjohnny

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The oil in a automotive AC system doesn't stay where you add it. It becomes entrained in the refrigerant and travels around the the entire system. GM specs the quantity of oil to be added to a purged system as below:

•Compressor- (1 ounce)
•Evaporator - (3 ounces)
•Condenser - (1 ounce)
•Accumulator (2 ounces)

When an R-12 system is retrofitted to 134a, the general rule of thumb is that the refrigerant capacity/charge should be reduced to 80-90 % of the original capacity.

The original GM spec for these trucks was 56 ounces of R-12. So, if we take 56 ounces of R-12 and multiply it by .85, we get a 134a charge of 48 ounces.

I always use 4 standard 12 oz (1 lb) cans.

To cause a noticeable loss of cooling capacity - by adding too much oil - you would have to add way more than you did. Try another can of gas...
I know this is an old thread, you seem to be pretty knowledgeable. I am replacing my condenser, hoses, and compressor. The evaporator and accumulator are still in great shape. The compressor came with 3 oz of oil in it. Should I have to add more since I am switching out the condenser too? The numbers you listed only show 1 oz for the compressor so I think I would be ok. Just don’t want to crater a new system. Thanks man.
 

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