AC Oil
#41
If you unhook both, you won't get a reading. Unhook the low side (blue) hose and see if the vacuum holds. Then hook it back up and unhook the high side hose (red). I've seen atmospheric pressure (14 psi) seep in but the system gets charged and not leak out. It depends on how strong the valve springs are. If you aren't worried about the valves, pump it down and take a 30-45 minute break and come back. If the vacuum is holding, charge it and go.
#42
If you unhook both, you won't get a reading. Unhook the low side (blue) hose and see if the vacuum holds. Then hook it back up and unhook the high side hose (red). I've seen atmospheric pressure (14 psi) seep in but the system gets charged and not leak out. It depends on how strong the valve springs are. If you aren't worried about the valves, pump it down and take a 30-45 minute break and come back. If the vacuum is holding, charge it and go.
#43
#44