Connecting pressure gauges
1 - side with high pressure; 2 - side with high pressure; 3 - low pressure; 4 - high pressure; 5 - side with low pressure; 6 - side with low pressure.
The air conditioning system with R-134a refrigerant has ports with "quick connectors" adapters. Each adapter features a female threaded sleeve to keep contaminants out of the system.
Order of execution
1. Close both valves on the line.
2. Connect gauge adapters to the appropriate ports.
3. Hand tighten the adapter hose nuts.