Automotive Air Conditioning Information Forum

I purchased a Denso 471-0316 compressor it states the compressor is filled with a complete charge of refrigerant. It instructs to drain the compressor and only put in what my old compressor had in it when replacing just the compressor. Since I have completely flushed the system of oil replaced the condenser and accumulator it seems I should be good to go and do not need to add any oil to the system with the new pump installed. I know my system oil fill is 11 oz (2005 Tahoe rear air). I did drain the oil from the new compressor and only got 2.1 oz. Does anyone know if there is significant oil that is trapped in the compressor and does not drain? I did turn the pump over repeatedly while trying to drain the oil. I am perplexed does the Denso pump have enough oil for the complete system or should I add more oil and if so how much? Any advice?

bville227 wrote:I purchased a Denso 471-0316 compressor it states the compressor is filled with a complete charge of refrigerant. It instructs to drain the compressor and only put in what my old compressor had in it when replacing just the compressor.

You mean complete charge of oil.

Aug. 2005, I replaced the compressor in my 2005 Yukon, see http://www.automotiveforums.com/vbullet ... aking+belt

The Denso instructions detail to measure the amount of oil remaining
in the existing compressor and subtract that amount from the oil amount already
in the new Denso compressor, but only about 1/3 of an ounce of oil came out of my old compressor,
even when I had it upside and rotated the compressor/pistons 10 revolutions. So
I didn't pull any oil out of the new Denso compressor.

bville227 wrote:Since I have completely flushed the system of oil replaced the condenser and accumulator it seems I should be good to go and do not need to add any oil to the system with the new pump installed. Any advice?

How did you flush oil out of the accumulator, does not seem like a recommended practice? Did you just drain it out, or use chemical solvent? I think a solvent flush of an accumulator could run risk of harming the desiccant bag. If me, if I had the accumulator off, I'd just replace it. Or do you mean evaporator, and if so just front or rear also?

Let me clarify I Flushed with solvent (used 2 qts) the Front and rear evaporators all the lines. I installed a brand new Condenser and new Accumulator. So I assume at this point my system has no oil except what was shipped in the Denso pump.

OK. Then I'd add a few more ounces of refrigeration oil. I'm not a pro, but guidelines are typically a couple of ounces for an evaporator or condenser and one for an accumulator, so in your case maybe add 6 additional ounces.

System with rear air calls for a total of 11 ounces of oil.

I doubt that there is 11 ounces of oil in that compressor as shipped.

Your best path is to drain the new compressor. Then add 11 ounces of oil to the system when you assemble it. Then you KNOW how much oil is in the system.

Thanks, BOHICA2X0 I agree it looks impossible for the compressor to hold 11 oz as shipped. I just re read the denso document and it states a The Compressor contains a COMPLETE SYSTEM CHARGE OF REFRIGERANT OIL but something must be lost in the translation. I will take your advice and add 11 oz of PAG46 to my system with the drained Denso Compressor. It is strange that I only got 2.1 oz out of the new compressor.

bville227 wrote:. It is strange that I only got 2.1 oz out of the new compressor.

I've heard stories of new compressors having zero to too much oil, I'd always drain it all out (turning the compressor) and measure it. And then add the right amount. I would NEVER believe that a compressor had sufficient oil for an entire system, lucky if it had correct amount just for a compressor replacement.

In 2003, a rebuilt compressor for my 1988 Mazda truck contained PAG oil for R134a, had to flush that all out as I stayed R-12. A month later co-worker bought rebuilt compressor of same brand for his 1990 Mazda sedan (R-12), and that one had R-12 mineral oil in it. So never trust.