Adding oil directly to a car's A/C Compressor

[Atreus21]

Hi fellas,

So I'm replacing the ac compressor on my Buick Rendezvous, and have now sworn never to buy anything GM again as long as I live.

At any rate, I ordered the compressor and it came dry. It's supposed to take 7 oz of PAG46 oil. As I understand it, you administer the oil through the low pressure service port, and rotate the pulley and clutch gradually as you add it.

But man, it just doesn't want to take the oil. Every time I rotate the clutch the oil bubbles up and overflows, sometimes rather violently, splattering oil over me and the surroundings. I try to add it more slowly, but it still tops off quickly and then I'm back to cleaning up overflows and wondering how much oil I lost relative to how much is required to be in the compressor. It's just a pain.

I know there are products that allow you to inject oil into the low pressure line with the compressor already in place, but I've read in many places that this is not advised for providing a compressor with a full charge of oil.

Anyway, was wondering if any of you guys have ever dealt with this. Thanks.

 

[Fardringle]

I haven't found anything specific for the Buick, but the few guides I can see say to put the oil in the Low side (large hole), then plug the holes before you rotate the pulley and clutch so the oil can't be spit out while the compressor is turning. Also, if the compressor won't accept any oil at all, it might not actually be dry and you could be overfilling it...

 

[kn51]

Did you also replace the dryer and orifice tube? Look in the hose for evidence of black death? Are you pulling the vacuum/recharging yourself or dragging it in somewhere?

 

[Atreus21]

I haven't found anything specific for the Buick, but the few guides I can see say to put the oil in the Low side (large hole), then plug the holes before you rotate the pulley and clutch so the oil can't be spit out while the compressor is turning. Also, if the compressor won't accept any oil at all, it might not actually be dry and you could be overfilling it...

I emptied any oil that came from the vendor, which they said was just to keep it lubricated during transit.

I tried plugging the hole and rotating the clutch, but when I open the plug the contents are under pressure and the oil literally pops out of the compressor. It might just be air trying to escape.

Did you also replace the dryer and orifice tube? Look in the hose for evidence of black death? Are you pulling the vacuum/recharging yourself or dragging it in somewhere?

I am replacing the compressor only. I've seen no evidence of black death.

I had a shop evacuate the existing refrigerant. I'm pulling vacuum and recharging it myself.

 

[kn51]

Have you looked into pulling oil in after pulling a vacuum with the manifold?

I'd replace the dryer...but I understand not to if it is a PITA, costly, or you just plain hate the POS vehicle.

Edit forgot to ask, did you yank the old one off yet and drain it to see how many ounces it has. Might be different than what the specs call for.

 

[Atreus21]

Have you looked into pulling oil in after pulling a vacuum with the manifold?

Yes, but I've read that this method is not recommended for delivering anything other than small amounts of oil to the compressor. I need to deliver 7 ounces.

I'd replace the dryer...but I understand not to if it is a PITA, costly, or you just plain hate the POS vehicle.

Edit forgot to ask, did you yank the old one off yet and drain it to see how many ounces it has. Might be different than what the specs call for.

I pulled the old compressor out, yes. It's sitting out on top of the garbage can - I'll see how much oil it has in it.

 

[kn51]

Ok, my thoughts are probably not much help just throwing out ideas that I've looked at in the past. I'm looking at a compressor change on my truck (long story on that...might go into detail. Yeah, probably will.)

Anyways, what made you decide it was the compressor? Reason I ask about the oil QTY is that is how much you should probably put back in. Not like baking a cake, an extra oz or so won't matter much.

On my Expedition, it of course leaks and has rear air so there are two evap coils, lines everywhere, etc. Threw in dye and at night crawling around with the UV light about the only trace I could find was underneath the compressor. Looks like the body of it is somewhat torqued. Or it could be coming from the front seal. But it was so dang minor I'm always second guessing myself on it. I was hoping to find some CSI crime scene with the light. Couple cans of refrigerant and she is good to go for a month or two. Yeah bad, but the alternative...

 

[Atreus21]

Ok, my thoughts are probably not much help just throwing out ideas that I've looked at in the past. I'm looking at a compressor change on my truck (long story on that...might go into detail. Yeah, probably will.)

Anyways, what made you decide it was the compressor? Reason I ask about the oil QTY is that is how much you should probably put back in. Not like baking a cake, an extra oz or so won't matter much.

The clutch wasn't engaging, and not for lack of refrigerant.

 

[kn51]

Gotcha. Clutch and coil wasn't a serviceable part?