Some breast pump accessories do need replacing regularly to maintain performance. If you notice that your pump seems to have lost suction, the first thing you should do is take a look at your parts, particularly the valves, and inspect for wear, fraying, or stretching and replace if needed.. 1. Diaphragm and duck valves need to be replaced every 3 months;. 2. Backflow linker and flange shields need to be replaced every 6 months
