This post covers milk backing up for both Freemie Original and Next Generation Cups.
Original Freemie Cups
When using the Original Freemie open-system cup set (model nos. FG041, FG047, FG031, FG017) milk in the tubing usually means something is not assembled or positioned correctly. In most cases, the silicone duckbill valve is either turned slightly, or not pushed all the way down on the valve base. If the valve is not horizontal and is able to touch the rounded portion of the cup, milk will back into the tubing.
Replace valves every 2-3 months for best performance
The most common circumstance we hear is that the pump was being used normally, and milk “just backed into the tubing randomly.” This is a sign your valves have likely worn out, and need to be replaced. They are available here (open-system).
Be sure your valves are COMPLETELY dry before using them. If parts are wet, they will not hold as well and can slip during pumping. Breast milk has fat in it and if milk residue remains on parts the valves can slide off. We recommend using a soap that removes grease when cleaning your parts (e.g., Dawn).
When assembling your cups, put the tubing in first, not last. Sometimes you can push the valve assembly off of the funnels (if inserted too forcefully). Take your time with assembly every time, and keep an eye on your lines.
Less common reasons for milk in tubing include:
- Bending over at hip
- Excessively jostling the cups
- Nipple bent in funnel
- Not having the cup tubing at 12 o’clock
Please check all of these things.
Next Generation Cups and Milk in Tubing
The closed-system cups have a barrier inside to prevent milk from going in the tubing. If a cup barrier gets torn, milk can get into the tubing and even the pump. Examine this part every time you pump. You can put the silicone duckbill valves on in any direction. Be sure to not lie down supine because this can allow milk to come out of the pour spout.