AC compressor oil amount

Status
Not open for further replies.

Bonnewagon

Rocket Powered Basset Hound
Supporting Member
Sep 18, 2009
10,540
14,217
113
Queens, NY
So I'm replacing an R-134 compressor and I read in the manufacturer's instructions that a compressor holds 60% of the oil. Thus in a 6 ounce system 4 ounces should be in the compressor. That is in direct contradiction to every factory manual I have. The factory says the compressor holds the least amount of oil. You drain the compressor, and if less than an ounce comes out, you add two ounces. If more than an ounce comes out, you add that much back. My system holds 6 ounces and since the old compressor held just a bit under an ounce, it should have seized up according to those instructions. It did not, it worked fine, I am changing it because the clutch went and a whole compressor is only a few bucks more than a new clutch. My gut tells me to stick to the factory specs and disregard the manufacturer's instructions. What do you guys think? EDIT: Yoiks! The system has PAG 100 in it and the new compressor says to use PAG 46. No way I'm flushing all the 100 out. :doh:
 
Last edited:

Longroof79

Rocket Powered Basset Hound
G-Body of the Month
Oct 14, 2008
12,156
9,762
113
Gainesville, Fl
Mark,
My new 134A system called for 8oz. total, using PAG150 with an R4 compressor.
2oz. in the compressor.
2oz in the accumulator
1oz in the condenser core
3oz in the evaporator
 
  • Like
Reactions: 1 user

Bonnewagon

Rocket Powered Basset Hound
Supporting Member
Sep 18, 2009
10,540
14,217
113
Queens, NY
Yeah Jack, 2oz is more like it. That's what I added. Then I looked around and found a chart of what oil all the OEM's use and it's all over the map as far as viscosity.http://www.greenvald.co.il/wp-content/uploads/2012/12/PAG_oils_application-05.pdfhttp://www.greenvald.co.il/wp-content/uploads/2012/12/PAG_oils_application-05.pdf It seems to depend on the compressor manufacturer. Here's what I am dealing with. Factory manual calls for ND-8 oil in the Nippondenso compressor. That's a 46 weight oil. But what the car had was a Sanden compressor with SP20 oil which is 100 weight. Date tag was for the year 2000 so it is original. So I get a new compressor thinking it would be the same, but no, it has a tag that says use 46 weight oil, like the manual states. But here I have a system that worked fine but is filled with PAG100 oil. As someone elsewhere stated- the oil is for the compressor which is the only moving part, so do as the manufacturer says. And how am I suppose to get the old oil out, flush a perfectly good system that has a new accumulator too? Sheesh. Then, looking around, no one stocks 46 weight oil anyway. 100, 150, plenty. No 46. So I figured better a heavier oil than a lighter oil and I topped it off with the 2oz of 100 weight. Someone else said that in the field, most technicians use only 100 weight anyway because it is universal and they only need to stock one type oil. So I vacuumed it down for an hour, it held vacuum for a half hour, vacuumed it some more, then added a small charge of R-134 just so that there is positive pressure in the system for now. And then I'll know if it leaks before I button it up for good. I can't start the motor and add the correct amount yet because the radiator is not here yet and the transmission line is disconnected. Keeping fingers crossed.:doh:
 
Status
Not open for further replies.

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor