Where is the refrigerant charging port on a BMW 318?

[Sanders]

For the BMW 318, the refrigerant (freon) is typically charged through the high and low-pressure ports of the air conditioning system. System vacuum evacuation: After evacuating the system, close the high and low-pressure manual valves on the manifold gauge. Connecting one end of the hose to the refrigerant canister: Attach one end of the center hose to the refrigerant canister injection valve fitting. Open the refrigerant canister valve, then loosen the nut on the manifold gauge hose to allow gas to escape for a few minutes before tightening it. Injecting liquid refrigerant: Open the high-side manual valve and inject the specified amount of liquid refrigerant. Closing the injection valve after charging: After completing the refrigerant charging, close the manual valves on the manifold gauge and the injection valve on the refrigerant canister. Stop the engine, then quickly disconnect the manifold gauge from the compressor to minimize refrigerant leakage.