1. Turn both valves on the R-134a Manifold Gauge Set all the way to the left to close the low-pressure and high-pressure hoses to the center manifold and center hose.
2. Remove the A/C charging valve cap from the low-pressure service gauge port valve.
3. Remove the A/C charging valve cap from the high-pressure service gauge port valve.
4. Connect the R-134a manifold gauge set low-pressure hose and the R-134a low side quick disconnect to the lo pressure service gauge port valve.
5. Connect the R-134a manifold gauge set high-pressure hose and the R-134a high side quick disconnect to the high-pressure service gauge port valve.
