I'll pull a vacuum just to see if it holds as a quick leak check. Then I'll pull it apart, flush the system out and replace the drier, tube and the EVAP core (if the compressor came apart) then swap the compressor. Then pull a vacuum and see if it holds. That lets me check for leaks and pulls any moisture out that got in while it was apart. For oil, the new compressor should come with oil, generally you drain the oil from the old one, measure it and add the same amount to the replacement. If however you had to flush the system I measure the compressor and then look at the total oil charge and what you drained out. Add the same amount you drained back into the compressor and the rest gets put into the rest of the system. GM went to a premeasured 8 ox cartridge on those vehicles, so say you drained 4 oz from the compressor, you would add 4 into it, then 2 into the EVAP core and 2 into the condenser core.
Aug 23, 2026 at 9:45 AM
