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2006 OutBean, 2005 LGTW
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Discussion Starter #1
Mine was shot so I picked up a used one from a wrecking yard. I'm wondering how much PAG oil I should add to the compressor before I drop it in place and bolt up the lines.

Thanks
 

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2006 OutBean, 2005 LGTW
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Discussion Starter #2
Oh.. I'm also replacing the drier/receiver as well so I'm not sure if that will require more oil
 

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OBW H6 VDC, Tribeca, XT6
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Simply put - i'd add 3 ounces or google it.

And an additional 1 or 2 if you're cleaning out all the lines or evacuating/discharging in such a way that a significant amount of oil comes out with the refrigerant, which i'd guess is likely in your case.

Quantifying it:

1. Drain the removed parts (as hot as possible to make the oil viscous), measure, and re-add that same amount to the new components. Clearly all the residual oil on the internal components won't drain out

2. Check the component manufacturers of new components and make sure they don't come pre-lubricated.

The problem with being precise is you won't really know how much you're "removing" since there's residual amounts in the original failed compressor. You won't know how much residual oil is contained in the new compressor either. And you won't know how much you loose in the refrigeration evacuation/discharge process.

Most Subaru's hold very roughly 6 ounces of oil. Removing those components you're "net loss" is roughly 3 ounces, then maybe a few more depending on circumstances.


Some points that make this not a big deal:

A used compressor typically comes off a running car and has the same residual oil in it that any operational compressor has. It doesn't really "need" any oil, you can used-compressor swap all day long without adding oil and it'll also pick up oil from within the existing system if needed. I'm not recommending that, i'm just saying it's rather benign and you can't really add "too little".

For those same reasons - no Subaru in the US is having oil induced A/C failures from replacement components from incorrectly oiling it. the outliers causing oil related failures to Subaru A/C compressors shouldn't be trusted with a gas pump, just joking...there's actually reasons to not care sometimes too.

It'll all disperse over an enormous amount of internal surface area so you don't have anything to worry about unless you're careless or trying to dork it up. Add it slowly over a period of time, and don't add it to the compressor.

They have far more than necessary in an operational system. it's not like they're going to fail if they end up with 9 drops less oil, or more. So you've got a relatively (to someone experienced anyway) operational range here, it's not that precise.
 

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2006 OutBean, 2005 LGTW
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Discussion Starter #4
Added your suggested 3 oz of oil, slapped it back together, pulled a vacuum on it to test for leaks. Held well, so charged it and it works great!

Thanks!
 
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