If only one cup seems to be working, the issue may be incorrect cup assembly, poor bra fit or breast flange size, damaged or worn parts, or incompatible pump use.
Most times, there is an issue with incorrect cup assembly. Please watch this assembly video to ensure you have the proper setup for SlimFit Cups:
When assembling the cups, insert the barriers into the valve bases.
Then firmly press the valve base and barrier onto the mounting ridge of the breast flange.
You should see both barriers inside the cups curling up and releasing when your pump is on maximum. If you don't see this, take the cups apart and re-assemble them.
View complete assembly instructions here.
Damaged Barrier Part
If you have the cups assembled correctly and only see/feel suction coming from one of your cups, you may have a damaged barrier part. Inspect the barriers under a bright light. Uncurl the edges and squeeze open to look for any damage. The barrier protects your pump and must be replaced if damaged.
If you have had milk back up into the tubing, a barrier part is probably damaged. Check the Y-connector and tubing parts for any dried milk, obstruction or clog. Replacements are available here.
Watch this video to see how to inspect a Freemie barrier part:
Size Issue
If you do not find damage, dried milk or obstruction on either barrier, but only seem to have suction on one side, try single pumping and swapping parts (i.e., valve bases, barriers, and valves) between the two cups to see if you can isolate the problem part. If this does not resolve the issue it could be due to cup positioning in the bra and/or breast flange fit. Both the bra and breast flange must fit well to have good results.
- Check that the bra is making a good seal between your tissue and the breast flanges and that no gaps occur when you move.
- Be sure that the breast flanges are comfortable and not sucking in your areolar tissue.
- Know that tissue can change over time, and you may need to either increase or decrease the breast flange size.
Check breast flange fit below (click to enlarge):
View additional flange fit information here.
View additional bra fit information here.
Worn Parts
Check that the valves are not damaged. Worn valves can cause low or no suction and should be replaced every 2-3 months. Replace sooner if use is heavy.
Soiled Parts
Always start a pump session with clean, dry parts that were just assembled. Look for any damage or obstruction such as dried milk, hair or a tear on the tubing.
Boil or Replace Parts
If there is no damage to the barrier parts, and valves are relatively new, be sure that you have boiled the hard cup parts. Boiling should be done before first use, and both sanitizes the parts and makes them airtight. See complete boiling instructions here.
Note that cup parts should all fit together snugly. If the valve base feels loose on the breast flange after parts have been boiled, replace it. Find new valve bases for the Slimfit5, here. Find valve bases for the Slimfit6, here.
Compatibility Issues
Freemie Cups work best with Freemie Pumps. When using an approved compatible pump, be sure that you have correctly connected the cups to the pump. There are no additional parts needed to attach the Slimfit Cups to a compatible pump.
One pump port on a compatible pump should always be capped for single or double pumping.
If you are not using a compatible pump the system can malfunction. Full the full compatibility list, click here.
View additional pump connection information here.