Disassemble a freezer to change capped capillary, I find a piece connected behind the evaporators (before removing the yellow insulating foam) between the evaporator of the freezer itself and the one inside the refrigerator itself, which is very similar to a cylindrical Moisture filter, so find out is a liquid trap, 1) is it called that? 2) Should I change it too? 3) Does it have a molecule inside? It catches my attention that it was very hidden covered by the foam or the sheet that covers the refrigerator behind, as if it were a piece that never changes? Thank you in advance and I clarify that I am fond of home repairs, not an expert.