Question: Momcozy M9 Duckbill Valve very hard to turn to lock | unlock?
Hi there! I’m a FTM trying to figure out what I am doing wrong with the duckbill valve on my M9s. I believe they are the newer model where the duckbill valve clips onto the main piece. Everytime I go to turn the valve to take it off to clean it or lock it back in for use it takes a lot of twisting and pushing to get it done. I’ve also developed mommy thumb (yay!) so the turning of this particular piece really agitates that. I’ve seen the TikTok where the lady explains how to leave the valve attached to the main piece as to not break the part that it clips on to but my issue is how to attach/take it off from the collection cup without it taking so much effort. If I am not understanding something and doing it wrong could someone please point it out? I’m starting to feel super discouraged about spending so much money on this pump as it was recommended to me by a family member and I was planning on using it primarily while pumping at work and during motn feeds to prep for the next feed. Any help is appreciated, thank you!
DuckBillValveFactory.com Answer:
As a DuckBill valve expert from DuckBillValveFactory here. You’re definitely not alone. This has been one of the most common complaints with the original M9 design.
The difficulty you’re experiencing with twisting the duckbill valve is almost certainly not user error, but a design flaw. It stems from an inherent conflict between two engineering requirements: the need for a robust hydraulic seal versus the need for a user-friendly assembly.
To prevent leakage under the pump’s high suction (up to -300mmHg), the valve and its mating port are designed with extremely tight dimensional tolerances. The friction required to create that leak-proof seal is unfortunately also what makes the twisting action so stiff. Many of the M9’s seven assembly parts must fit together precisely, so any minor molding imperfection or residue can make the valve much harder to turn than intended.
🔧 Actionable Solutions
Lubricate the valve. Apply a tiny drop of food-grade silicone lubricant (or even a dab of coconut oil) to the O-ring-like ridge before inserting. This is an industry trick for sticky pneumatic seals.
Try a “break-in” period. If the pump is brand new, the friction may decrease after 2–3 full disassembly cycles as the silicone surfaces naturally burnish against the plastic.
Use grip aids. Wrap a damp paper towel or rubber dish glove around the base of the duckbill. The extra traction allows you to twist with less force, putting less strain on your thumb.
Replace the valve. If the valve remains impossibly stiff, it could be a manufacturing defect where the silicone is out of spec. Try a fresh pack of official M9 replacement valves or third-party brands designed for the M9.
🩺 On “Mommy Thumb” (De Quervain’s Tenosynovitis)
Regarding the pain from turning the valve, here are some low-strain techniques to protect your wrist and thumb:
The “Palm Twist”: Instead of pinching with your thumb and forefinger, press the valve against your opposite palm with your hand flat. Use your whole arm to rotate, keeping your thumb completely straight and still.
The “Two-Hand Grip”: Hold the collection cup in one hand. Place the heel of your other hand on top of the valve and press down firmly while twisting at the wrist, keeping your thumb free.
Use a tool as an assistive device: Slip the flat handle of a butter knife or a dinner knife through the valve’s tab. Use it as a lever to twist, keeping your wrist in a neutral position.
⏰ Maintenance & Replacement
Replace your duckbill valves every 2–3 months for optimal suction. Worn valves with tiny cracks or stretched lips will cause a noticeable drop in milk output.
Always inspect new valves by holding them up to a light. If you see a visible gap between the silicone lips before they are ever used, they are defective and should be returned.
Clean by soaking in warm soapy water. Do not use brushes on the delicate lips, as scrubbing causes micro-tears that drastically shorten the valve’s lifespan.
💎 Final Takeaway
The stiff rotation of the M9 duckbill valve is a frustrating but well-known trade-off for its leak-proof design. You’re not doing anything wrong. By applying a little lubrication and using the low-strain hand techniques, you can make assembly much easier without worsening your “Mommy Thumb.” Please don’t feel discouraged about your investment – once you get past this learning curve, the M9 is an extremely effective wearable pump.