When I had mine done at Compressortech they suggested replacing the orifice valve as well. The old one they took off had quite a bit of debris in it so was a good call. Problem though is this valve is under the dash and is a dash out job to get at it. They also used a gallon of A/C flush fluid to clean the pipework. Overall not a cheap job but 100% confident that it was working correctly, no noise and cold air.