AC Question: Is AC oil removed when system is vacuumed?

[dsagers]

I am about to add the oil to my 1994 Q45 AC system after replacing the compressor and flushing the system, and a new receiver dryer.

A local shop has a real nice AC machine to pull a strong vacuum for half an hour or longer if I want. Wondering how much oil will be sucked out of the AC system when its vacuumed?

[Q45tech]

Usually 2-3 ounces depending on the machine and time 30 minutes or 1 hour of vacuuming.

[elwesso]

is that from a discharge or even just a vacuuming on an empty system? 2-3 ounces is appreciable and I wouldnt think that much would come out on just vacuuming after the system is discharged.

[Q45tech]

During the vacuum down from full charge a quality machine separates the oil into a special graduated container. Why such quality machines have a special system to add new oil as new R-xx is installed.

CAREFUL about adding too much oil as even 1 ounce over normal starts to degrade performance by a degree or two. It rises exponentially after the first extra ounce.

[dsagers]

Guys, big thanks for the help.

I'm now calling local shops to find one that has the type of machine that measures the oil removed from the system.