When using our Freemie Original open system cups for Medela pumps, if you get milk in the tubes it usually means something is not assembled or positioned correctly. In most cases, the silicone duckbill valves inside the cups are either turned slightly, or not pushed all the way down onto the valve base. Worn out valves are also a common cause for milk to back up. Replace your duckbill valves every 2-3 months for best performance. If cleaned immediately, soiled tubing can be rinsed out with hot soapy water.  Replace soiled tubing if unable to clean.

See below diagram for perfect valve position.

When assembling the cups, put the tubing in first not last. Sometimes you can push the valve assembly off of the breast funnels (if inserted too forcefully). Take your time with assembly each time. See below Cup Assembly diagram.

Less common reasons for milk in tubing include: reclining, bending over at hip, excessively jostling the cups; nipple bent in funnel; overfilling past 8 ounces; not having the tubing at 12 o’clock.