Help - flushing out wrong oil from AC system

[jm_vectrab]

Hello everyone,

I have a 99 GM/Vauxhall Vectra that had a leak and I fixed by replacing some components, but did some mistakes along the way and need help to come up with a plan now... in fact not even using it until I can address --->AC is working and cooling fine btw.

First, it uses a Delphi Harrison V5 compressor (still original from 99) that calls for 7.5oz of synthetic oil SAE J639

I have never worked with AC before and didn't know they had different oil viscosities too... thought it was one fits all or period specific, asked a shop and the guy said "we mostly use PAG46" so I went with it.. yes very dumb mistake, it should have PAG150 it seems... 1st error.

also when replacing hoses, cleaning etc, I am sure moisture entered the system... I washed the compressor insides (just the casing not the part were the pistons are, but still) and hoses were open for a while... 2nd error. (added a new dryer filter at least).

What is the best way to remove oil without disassembling everything again now? if the shop pulls vacuum from the high pressure/liquid side, will it work? I can also remove the fill bolt in the compressor and use a syringe to remove most in the sump there...

Also by researching this, found some saying that running too much/deep vacuum can boil the oil and damage seals, is that true? I refreshed most things and don't want to put at risk... just not sure how it is possible/works.

Thanks in advance!

[JohnHere]

I have a 99 GM/Vauxhall Vectra... .

Yours is not a USA-spec vehicle, so I don't have any information on it.

I have never worked with AC before and didn't know they had different oil viscosities too... thought it was one fits all or period specific, asked a shop and the guy said "we mostly use PAG46" so I went with it.. yes very dumb mistake, it should have PAG150 it seems... 1st error.

See "Auto AC Forum Posting Rules", Number 1.

In that same vein, realize that Mobile Vehicle Air Conditioning (MVAC) system diagnosis and repair requires extensive knowledge; years of training, experience, and observation; in addition to the right tools. You can do expensive damage to an MVAC system—or more importantly, injure yourself—by arbitrarily working on a system or by adding unknown quantities of refrigerant and oil. A system is designed to operate on a specific weight of refrigerant and a specific type and quantity of oil. Too little is a problem, and too much is also a problem. Unfortunately, you can't diagnose any system with one of those "quick-fix kits" readily available from discount or auto-supply stores.

That said, what you did isn't dumb...just a mistake due to inexperience and lack of knowledge.

As you correctly pointed out, though, the main difference between PAG-46 and PAG-150 is viscosity.

also when replacing hoses, cleaning etc, I am sure moisture entered the system... I washed the compressor insides (just the casing not the part were the pistons are, but still) and hoses were open for a while... 2nd error. (added a new dryer filter at least).

Air and moisture definitely entered the system while it was open, but a thorough evacuation before recharging the system would've eliminated those. Sounds to me like evacuation wasn't done, unfortunately. So you still have air and moisture in the system, even though you replaced the receiver/dryer (R/D), which will remove some of the moisture (until the desiccant becomes saturated), but not air.

Disassembling the compressor, solvent cleaning only the case but not the piston assembly, probably was okay as long as you blew-out and dried any remaining solvent beforehand. This presumes that you didn't introduce any dirt or grit into the compressor on reassembly.

Did you also replace the shaft seal while you had the compressor apart? If not, the seal might leak at some point in the future.

What is the best way to remove oil without disassembling everything again now? if the shop pulls vacuum from the high pressure/liquid side, will it work? I can also remove the fill bolt in the compressor and use a syringe to remove most in the sump there...

If the shop recovers and evacuates the system now, *some* oil will come out, but only a small amount.

Here's what I recommend that you do: Have the shop recover the refrigerant, disconnect and remove the compressor from the vehicle, unscrew the drain plug, invert the compressor, and let the oil drain-out overnight into a graduated container. Hopefully, you will have drained-out 4 or 5 ounces. Next, replace the PAG-46 you drain out with the identical amount of PAG-150. Then replace the R/D again, evacuate, and recharge the system to specs (or have the shop do it). Whatever small amount of PAG-46 that remains in the system will mix with the PAG-150 on running the system for the first time. In my humble opinion, running the system containing this small amount of PAG-46 won't hurt anything.

Also by researching this, found some saying that running too much/deep vacuum can boil the oil and damage seals, is that true? I refreshed most things and don't want to put at risk... just not sure how it is possible/works.

I have never heard of or experienced that happening. But I would replace all of the o-rings and gaskets in the system while you have it apart.