Forum β€Ί Injection Technique

Crooked Cartridge?

11 replies3 peopleJun 11, 2026β˜† Follow
Summary

why does a cartridge stopper sometimes sit crooked and resist pushing, and how do you fix it without new supplies

Users found that roughly half the cartridges arrive with the internal plunger seal installed backwards, creating extra friction that some pens cannot overcome. One person confirmed the issue by inspection and now checks orientation before loading. Others temporarily freed stuck stoppers by adding a little BAC water underneath and pushing air through the top, though they noted the method is not sterile. No one resolved whether the backwards seals can be safely corrected or if the cartridges should simply be set aside.

What this discussion establishesStill open

whether backwards seals should be flipped or the cartridges simply discarded

Nothing here is advice.

11 replies Β· 3 people
PatientAlder89archiveopening postJun 11

Has anyone had your cart stopper moving crooked and hard to push? What was your solution?

BlueAlder28archiveJun 11

Sure, the issue's still there and I ought to handle it. Being stuck way out here leaves me without any backup cartridges or ways to order replacements. I did bring a few basics though like extra insulin needles, some strainers, and sterile water. My plan is to let a drop of that water run along the cartridge bottom then push in some air from the top to nudge the plug lower before testing it out. The other choices are hanging around for a couple months until the next chance or pulling the stuff into needles for the usual manual shots, but neither sounds good to me.

PatientAlder89archiveJun 11
↳ replying to @BlueAlder28

Got my pen topped off just now. Probably the plunger didn't seat right inside it. Never occurred to me to double-check that step earlier. Maybe a few cartridges just turn out bad sometimes? Not sure, haha. This is my first time trying it.

BlueAlder28archiveJun 11

Maybe the right way to handle this is drawing every bit of liquid from the old cartridge using a three milliliter syringe, running that through a filter, then moving it all into a replacement one. What cartridges does everyone else have? The ones I own came from a big online retailer, as best I recall. My pens came from a specialized site.

PatientAlder89archiveJun 15
↳ replying to @BlueAlder28

Got a few recently. The issue probably came from how I filled the cartridge pen. I should watch how I position the rod that forces it forward. It was likely my own oversight from not focusing enough. Not certain though, you know.

BlueAlder28archiveJun 15

Earlier today another one got stuck for me. I cleared it using the technique I mentioned previously and it succeeded both times. I added a little BAC water to the lower part then forced ten units of air in from the upper section of the cartridge to free it. I realize this isn't the most hygienic approach. Given my current isolated situation it is the only thing I can manage for now.

GreyAlder39archiveJun 15
↳ replying to @PatientAlder89 (opening post)

I notice that around half the usual cartridges arrive with the rubber seal flipped the wrong direction. The wide portion needs to face the side where the piston pushes. Comparing it to an ordinary insulin syringe makes the orientation obvious. Certain injectors supply enough pressure to move the piston despite the added drag. This setup works fine in a couple models but struggles in others and fails completely in particular versions.

PatientAlder89archiveJun 15
↳ replying to @GreyAlder39

I'm wondering if pulling it out and putting it back in would solve things. But then it probably wouldn't stay clean anymore, would it? This is really annoying. I need to figure out whether that's actually the case, or if the mechanism inside my device is just misaligned.

PatientAlder89archiveJun 15
↳ replying to @BlueAlder28

I'll try some other approaches since I'm likely not receiving the proper amount while fixed in this position.

PatientAlder89archiveJun 15

You verify the alignment isn't off every single instance prior to installing the cartridge and reserve any off ones to test at some point in the future?

GreyAlder39archiveJun 15
↳ replying to @PatientAlder89

They arrived each in sterile individual wraps inside a single plastic bag containing ten. After checking all ten, I'm hoping the upcoming bag yields more than five usable ones. Trying calibration on assorted pens appeals to me, yet there's no hurry.

PatientAlder89archiveJun 19
↳ replying to @GreyAlder39

Turns out you had it spot on after all. Once I double checked everything really was reversed. Now I can spot the signs right away. Thanks so much for the heads up! πŸ™‚

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