How much PAG 46 On AC compressor/drier change?
 

My AC compressor crapped out. I have a new Behr compressor coming. I have a vacuum pump. I have a new dessicant for the drier in the condenser unit. I've got R134a. I've got PAG46 and I've got 4-way AC guages.

I think my parts list is complete to get this AC swap done. But I have no idea how much PAG46 I'm supposed to use!

I know I'm supposed to measure how much oil comes out of the old compressor and put that amount in the new one.

But I also know there's some in the receiver drier that I'm replacing. I can't find how much to add to compensate for new dessicant in the drier?

Also, I plan to pull vacuum on the AC system to do a proper refill especially given how humid Florida is right now. Does pulling vacuum suck any oil out of the system I need to compensate for as well?

I haven't done an AC system since my Camaro's R134a conversion back in 2001, so I don't really remember anything about it and learning from scratch.

Thanks! :-)

I think the E53 X5 "may" be a bit more than E39 5-series.

I replaced the AC compressor on my 1998 528i at 160K miles and wrote a DIY here...

DIY: 1998 BMW 528i 160K Replacing AC Compressor

https://www.bimmerfest.com/threads/d...ressor.924320/

- The vacuuming process does not remove much PAG oil.
Probably nothing.

- Most of the PAG oil is in the compressor anyway.
Some compressor comes prefilled and some leaked PAG oil during shipment.

- Best is to drain all the PAG oil out of the new compressor and fill it using info in this thread...

https://xoutpost.com/bmw-sav-forums/...ll-volume.html

It's odd that AllData also doesn't specify the type/quantity of compressor oil.

You do need 430-450g of R134a.