When to replace your breast pump parts
By The Zomee Team · Updated July 12, 2026
Replace your pump's duckbill valves and diaphragms every 1–3 months, depending on how often you pump and how you clean them. If suction has suddenly dropped on a pump that used to work fine, a worn part is almost always the reason, and it is a much cheaper fix than a new pump.
The soft silicone parts do the hardest work in a breast pump. Every session stretches the valves and flexes the diaphragms, and over time they stop sealing the way suction depends on. This guide covers which parts wear out, what wear looks like, and the cleaning habits that make each set last.
Weak suction is usually a parts problem
When suction fades on a pump you've been using for months, the motor is rarely at fault. The most common cause of a sudden loss of suction is worn out or damaged parts, and duckbill valves top the list. Leaking works the same way: it is a parts issue, not a pump issue.
A brand-new pump that feels weak is usually a different story. There the likely culprit is flange size, since many moms need a size other than the ones included in the box. If the diaphragms are moving but little milk is coming, re-measure before you replace anything. When the shields that came with your Zomee pump aren't your size, The Perfect Fit Promise gets you a pair in the size you need at no cost, and The Mom Line™ can help you measure.
Which parts wear out and what wear looks like
Check the silicone parts every few weeks. Wear shows up in ways you can see once you know where to look.
- Duckbill valves pull the milk you express down into the bottle. Regular use stretches the slit at the tip wider and wider, and a wider opening means weaker suction. A fresh valve rests closed; a worn one gapes open, looks cloudy, or shows small tears.
- Diaphragms, sometimes called membranes, contract and release to draw your nipple gently in and out of the flange. With use they develop tears, and even a small one can leave you with weak suction or none at all. Look them over for thin spots and splits when you wash them.
- Breast shields can warp, especially with frequent high-heat cleaning, and a warped shield won't seal against your breast. Fit changes too: flange size can shift between pregnancies, so re-measure with each baby rather than assuming your old size still fits.
- Tubing needs no routine washing or replacing, because the anti-backflow design keeps milk out of it. That protection only holds while the parts around it are fresh.
How often to replace pump parts
Zomee recommends replacing pump parts, duckbill valves and diaphragms above all, every 1–3 months. Where you land in that range depends on how often you pump and how you clean: a mom pumping eight times a day wears through valves faster than a mom pumping twice, and frequent sterilizing shortens the life of every silicone part. Between those guidelines, trust what you see. A stretched valve and a session that suddenly runs long are telling you the same thing.
Check the box before you order, because Zomee pumps ship with extra duckbill valves and you may already have a fresh set waiting. When you do restock, the Zomee Z2/Z1 Duckbill Valves come as a set of two, and some insurance benefits cover replacement parts and accessories. Your provider can tell you whether yours does.
Cleaning basics that make parts last
How you clean decides how long each set of parts lives. The habits are simple:
- Hand wash after every session with warm water and mild dish soap. It is the method Zomee recommends, and FDA and CDC cleaning guidance supports hand washing as the preferred way to remove germs.
- Sterilize washable parts before first use, then only if your doctor advises it. Constant sterilizing warps silicone faster than you'd expect.
- Breast shield kit parts are dishwasher and steam sterilizer safe, but high heat can warp them so they need replacing sooner. Save it for when you need it.
- Let everything air dry completely before you reassemble.
- Never wash the tubing. Milk shouldn't reach it, so there is nothing to wash.
- Away from a sink, alcohol-free cleaning wipes cover the in-between wash-ups, with a proper wash to follow at home. The Breast Pump Cleaning Wipes are individually wrapped, so a few can live in the diaper bag.
Spare parts kits for the Z2 and Fit
Restocking one part at a time is how a mom ends up pumping on a worn valve for three extra weeks. The Zomee Z2 Spare Parts Kit puts the wearing parts in one order: the full breast shield kit in your flange size, a fresh set of duckbill valves, and cleaning wipes, priced below the pieces bought separately. The Zomee Fit Spare Parts Kit does the same for the Fit, with a full breast shield kit in your size, cleaning wipes, and milk storage bags, so one set dries while the other pumps.
And if you're reading this before you've chosen a pump at all, the pump quiz will match you to one in three questions. Whichever you pick, the parts that keep it pumping strong are easy to restock.
Questions moms ask
Why did my pump suddenly lose suction?
Worn parts are the most common cause, especially duckbill valves. Replace the valves and check the diaphragms for tears before assuming the pump itself is broken. If a brand-new pump feels weak, flange size is the usual reason instead.
How do I know a duckbill valve is worn?
Look at the slit at the tip: on a fresh valve it rests closed, and on a worn one it stays stretched open. Tears, cloudiness, and suction that feels weaker than it used to are the other signs.
Can I put Zomee pump parts in the dishwasher?
Breast shield kit parts are dishwasher and steam sterilizer safe, but high heat can warp them so they need replacing sooner. Hand washing with warm water and mild dish soap makes each set last longer.
Do I need to wash or replace the tubing?
The tubing needs no routine washing, because the anti-backflow design keeps milk out of it. If you ever see milk or moisture inside, stop pumping and contact The Mom Line, since that points to a worn part and can damage the motor.
Does insurance cover replacement parts?
Some insurance benefits cover replacement parts and accessories. Coverage varies by plan, so ask your provider what yours includes.
