Inside the metal tube running from the evaporator is a special fil- ter/valve called an orifice tube. It’s a critical part of an A/C system because it helps control the flow of refrigerant through the system— and filters out debris that could kill the compressor. It’s removed by using long-nosed needle-nose pliers and pulling straight up. Our old one was plugged with debris from the failed compressor. We dribbled a little GPD A/C Flush into the lines and used com- pressed air to blow it through them to clean out any debris from the compressor. A paper towel over the lower tube keeps us from getting a face full of flush! Once the line is clean, we added
the bottle of PAG oil to help lubri- cate the compressor after the sys- tem is filled with Freon. Oil comes with the new compressor.
With the line cleaned and oiled, we installed the new orifice tube that came in the kit. It pushes into the tube and locks in place.
Reconnect and tighten the line running from the evaporator tube to the condenser. If the line looks bad, replace it. Ours was still in good shape even after 20-plus years. We also replaced the keep- er spring at the connector and all O-rings we came across, all of which were in our A/C compressor kit.