Before beginning this procedure, refer to the precautions at the beginning of this section. Only a MVAC-trained, EPA-certified, automotive technician should service the A/C system or its components.
Evacuate the system until the low-pressure gauge reads at least 99.4 kPa (29.5 in-Hg) (vacuum) and as close to 101.1 kPa (30 in-Hg) as possible. Continue to operate the vacuum pump for a minimum of 45 minutes.
Turn off the evacuation pump. Observe the low-pressure gauge for five minutes to make sure that the system vacuum is held. If vacuum is not held for five minutes, leak test the system, service the leaks, and evacuate the system again.