How to change my inset and fill the new cartridge- Need help!

Hello T Slim users,

I'm trying to change my pump cartridge and put a new inset in- I have regular insets with the little plastic insertion device and I can't remember any of what to do :-(

I knew this was going to happen and I should have had all of the directions written down.

Are there any videos I can watch or can someone please help me with directions?

I'm only on saline so far fortunately, lol.

My inset directions seem to be saying that I need to connec the inset to a syringe and the pump and to fill the tubing somehow before I insert the inset into me, is this true? I don't remember doing that when I trained, in fact it is ALL a blank now...


There are instructions on placement in the Inset box. There are instructions on the other steps included with the t:slim.

You can fill the inset tubing while it's connected to the infusion set or not, but it should NEVER be connected to your body while you fill it, because they you might give yourself an unintended insulin dose.

After you fill the tubing and connect it to your body, then you fill the cannula, the little part that's in your body.

The syringe is used to fill the new pump reservoir, not the tubing. I think some do prime their tubing with a syringe but the official way is to use the pump to prime the tubing. People complain about how long it takes compared to other pumps, but it can't be more than maybe two minutes to fill the tubing.

Thanks Niccolo,

ok, I think I'm still pretty confused though, how do I fill the tubing do I just connect it to the pump at the luer lock, and then how does it get filled? And after that I then attach the inset to me with the tubing attached and filled?

I can't remember how we did this at all, but I seem to remember putting the inset on first and then filling the tubing etc. and then maybe attaching the inset after but that doesn't seem possible now because it's already attached in the insertion device obviously. But this was after we did the pump cartridge filling and so on.

How do you get it to fill the canula?

Why don't they make a video for this? Dexcom has one and it made it a lot easier for me although it still took me several times before I really remembered what to do.

So far, I really hate all of this, it is a pain carrying this thing around with tubing attached to you all the time imo, especially at night, the day is not so bad.

I'm about ready to give up on this now from the stress it is already causing me. Injections are so much easier than this.

I imagine there are videos online. A quick google for "t:slim infusion" turned up lots:

It gets easier! I've had mine for a few weeks, initially it annoyed me, and now I can't imagine living without it.

One thing that's been immensely helpful is the SPIbelt for diabetics, because it means that my pump is independent of my clothing, so I can drop my trousers to go to the bathroom, for example, and the pump just stays put around my waist. Or I can get fully undressed, and again the pump just stays put around my waist. And it can be worn either over or under clothes. And it's fantastic at night, because it's low profile so it can be worn all night, which I do.

Personally, I start the loading process on the pump, which suspends insulin delivery, remove the old infusion set, place the new infusion set, unclip it, remove the old cartridge from the pump, put a new cartridge in the pump, suck extra air out of it, fill it with insulin, fill the tubing, reattach it, fill the cannula, and I'm ready to go.

Some people prefer to fill the tubing before they place the infusion set, but I like the place the new infusion set and then let it sit for a few minutes before I infuse insulin through it, I figure that gives the wound at least a few minutes to settle down, but whether that actually makes any sense I don't know.

I think I will try that, how do you get it to fill first the tubing and then the cannula though? is there a button to press for each one in the menu?... I will check the manual.

I will look for a video, I have emailed my trainer etc. hopefully someone will respond too. I bought a little passport stretch wasteband thing but I really don't want to wear something like that constantly and I can't wear things under my clothes too uncomfortable etc. I think that is easier for men. I can't wear anything too tight either. Clips are useless, every time I have tried those to keep devices attached to me they just fall off. Going to the bathroom is a pain too while dressed, royal pain even with it in my pocket. I'm trying to conceal the tubing under clothes but it just keeps popping out which means it could get caught on things, but you can't clamp it etc because it could be damaged and then you can't go to bathroom or various other things. There has to be a better way to do this. I think omni pod might have been a better choice for me now.

There's a screen to do this whole process on the t:slim, and it includes all the various steps. It does sound like you need to go back to the manual, you're basically asking about everything, not just a step in the process. Hopefully going back to the manual will jog your memory from when you did this with the doctor/educator.

The OmniPod has some significant trade-offs, too, though. E.g. bulky pod stuck to you with much more robust/harsh adhesive, more crude capabilities, significant failure issues. You can get a trial pod to wear to see how you like it, will at least give you a sense of what it's like to have it attached to you.

I'm just back to this now- I'm reading the manual and pump screen, I have put a new cartridge in, filled the cartridge and filled the tubing, however there seems to be a major problem, it's telling me to fill the canula before I put the inset in or before I attach it and my inset etc. is in a big plastic contraption with the tubing connected so there is apparently no way to get the inset into me without the tubing and canula attached, can I fill the canula after I insert the whole thing? I have regular insets. Why is this so complicated?

On top of that, I stopped to try to figure this out how to get the tubing cannula device detached and put the inset in and the pump has now apparently stopped the whole process and wants me to add and fill a new cartrdidge now.. this is ridiculous, how could that happen?

The pump will freeze the process, but at least in my experience, you can always resume it. Maybe there's some period of time after which it forces you to start over? I suppose you could try to remove insulin from the cartridge with a syringe and see if the pump's air removal routine still works?

The reason you have to fill the cannula, after it's inside you, is that there's a steel needle filling the cannula until it's inside you. So there's literally no way to fill the cannula as long as that needle is in place.

This will be routine for you soon! For now, I'm thinking maybe you're best served making an appointment to have the nurse or your Tandem rep walk you through the process again. Or at least have them do so on the phone. Tandem has amazing customer service, at least in my experience, so reach out to your rep and/or doctor's office. My two cents, anyway.

I'm sure it has its own problems but at least there is no tube. For some reason I convinced myself that it wouldn't be too much of an issue but it seems like it really is now for me now that I actually have to do all of this. Maybe in time it will get easier. I have another problem already which I will post about with pain & tenderness at the inset which will be an even bigger problem though if it keeps up.

I'm happy to say that I finally got this done. I had to call tandem support for help though and then the menu issue happened again while I was on the phone. I'm wondering if something is wrong with my pump? It seems like a really bad idea to allow the pump to go out of that menu in the middle of things and then force you to go through previous steps again creating more work. We had to do fill the cartridge twice, inject more saline, it was such an ordeal for the first time doing this alone. But maybe I will look back and laugh about it eventually.

The person I spoke with said that it would be almost impossible physically for the insulin in the tubing to get into you if it were damaged or the luer lock somehow was undone: you would have to be in a pressurized area like the cabin of a private plane, be lying down and have the pump and tubing raised up above your head, like an iv, and it would take 30 minutes. That definitely makes me feel safer. I hope he's right! I plan to test it out with an orange maybe. I noticed that when I removed the inset and then undid the luer lock to start the refill process some of the saline came out from the luer lock end and none from the needle/inset end but of course it's not in the same circumstances as having the inset in place.

I think either I did that, waited too long, although it really wasn't long at all, or I pressed a button which took me out of the menu, but neither should be possible and then you have to do things all over, not a good program if that's the case. I hope something isn't wrong because I can't fathom going through this each time. As I said below it happened to me on the phone again and we had to go through the fill process etc. all over by which point it needed more saline again! omg

I see, I didn't get that about the cannula. I'm feeling ill now because I have messed up my basal dosing tonight, but will reply later with a better explanation maybe and with more details. I did end up calling Tandem... thanks for all your help!

Hi! I'm also using the TSlim and 90 degree Insets.

I personally like to fill my cartridge (go to options, load, then fill cartridge and follow the instructions), insert my new infusion set, disconnect from my infusion set (pinch the clear plastic on the side of the infusion set and pull away), fill my tubing, reconnect to my new infusion site, and fill my cannula. My pump rep wants me to insert my inset last and fill the cannula, but I like to insert my infusion set as soon as possible so that it gives me more time to determine if the site is alright (am I bleeding into the cannula? Is the site painful? etc.).

If you are a bit confused on inserting the insets, I know Diabetic Danica has a Youtube video instructing how to insert them ( -from about 4:00 until 7:00). This video also goes through the steps for loading the TSlim (

Hi Mimikins,

That is what the dexcom tech I spoke with told me to do: detach old inset, load, fill cartridge, fill tube, attach new inset and then fill the cannula. He said not to fill the cannula first for some reason which I can't remember now but he said not to fill the tube when it's attached because you could accidentally dose insulin- I think? But I'm not sure how. The first inset change was an ordeal with having to fill the cannula 2-3 times, air bubbles in the needle and the menu locking me out of the whole thing and forcing me to start all over.

I am having pain with these insets now although when I tested this one out to see if I could even use a pump I didn't even feel it at all(tested 3 different ones) and forgot it was there. I think this is due to actually having the saline etc. being infused into me so if I go ahead with insulin I will have to see if I can tolerate this. The first inset was more painful on my stomach but the second is still painful, not as bad, on my hip area where I'm less sensitive.

Do you know if there is an inset that could be less painful maybe? I'm not even sure what is causing the pain for me but there is no bleeding etc. So I guess it is just having the cannula in me and the fluid. I had a larger red hole when I removed the first one I used with actual fluid/saline, it seems to be healing up fairly well with some antibiotic cream.

I will check out her video, I have watched one or two or them in the past. Thanks! Tandem said they had some videos but had taken them down due to changes in the process and they will have new ones soon.

You're worrying me a bit with what you wrote.

As I wrote you before, you cannot fill the cannula (the little teflon tube that sits under your skin) before you insert the infusion set because it is filled by the steel needle that helps you place it. You also cannot fill the cannula before filling the tubing because the cannula is at the end of the tubing. Take a good look at a used infusion set to try to understand how the whole shebang works.

You said you had to fill the cannula 2-3 times. The cannula is inside you when you fill it. The inset requires 0.3 units of insulin to fill. So if you did it three times, you would have injected 0.6 units of insulin into your body, and filled it. Maybe you meant the tubing?

What does air bubbles in the needle mean? When filling a cartridge, many of us find that before filling, it's helpful to insert the syringe into the cartridge and suck out a little extra air. This is not a suggested Tandem procedure, however, and the pump tries to remove excess air itself. Cleaning air bubbles from a syringe is pretty straightforward, hopefully the rep showed you how to do that when you were set up.

There are many infusion sets you can try, including angled and 90 degree, teflon and steel needle, manual and auto-inserter. Your rep should be happy to give you various ones to try and see what you like best. Try to be as specific as possible in describing the pain and the circumstances under which it occurs and perhaps we or your rep can help you diagnose what's going on.

Sanitizing the hole with an alcohol wipe is a good idea. But unless there's an infection, you want to be careful not to get alcohol, or antibiotics, into the hole as much as you can avoid it, it'll just kill healthy tissue and impede healing.

You should NEVER fill the tubing while it's attached to you because, as you wrote, any overflow will overflow into you, i.e. you will give yourself insulin.

I had to refill the cartridge not the cannula. I didn't fill the cannula first and I didn't fill the tubing while it was attached- I did what the tandem rep helping me told me to do- which was fill the cannula after it was attached and he also said never to fill the tubing while attached. We had to refill the cartridge 3 x, once I did by myself when it locked me out of the menu. Then it locked me out again!!! while I was on the phone with him.

This forces you to go through the fill process all over again, and you have to do that otherwise the pump doesn't know how much insulin it has. You have to fill the tubing all over again which pushes more saline/insulin out so I had to inject more saline into it. It was a pain in the neck to say the least, so the menu/program needs to be changed so you can't get locked out by any means and have to start over again.

I tried 3 insets by themselves prior to deciding if I could even use a pump because I'm so sensitive- this one- regular, a deeper angled plastic one which was painful and the 90 metal one which was also painful. This one didn't cause pain without saline but it's causing pain now with it. I will ask her if there are others I can try- I think the saline is the problem though and it isn't going to be different with insulin probably, Maybe worse.

I'm not sure what is going on, yes she showed me that but each time I put saline in the syringe I end up with a huge air bubble at the top.. I just hate doing this stuff period. She told me to draw the syringe back to the dose, put the air back into the vial and pull out the fluid but then each time = huge air bubble. So I have to shoot some out and then you end up with not enough- with saline it is ok I guess although yesterday I was worried I would run out of that for the next cartridge. With insulin it won't be ok to waste so much. I put some antibiotic ointment on and it seems to be healing up fine so I will just put a dab on next time and see how it goes. Don't worry I will not fill the tubing while attached to me for sure.. maybe they should have some sort of alert for that too.

I experience the same air bubble when drawing up my insulin. I typically need to draw up roughly an extra 30-35 units to account for it. In total, I draw up about 170 units, use 30-ish getting out all the air bubbles, about 20 for the tubing fill, 90 for three day's worth of average insulin needs (TDD is about 25 units, but I like being on the safe side, especially if I need to use the extra insulin repriming, temp rating, or eating more food), and I have 25-30 units of insulin left over to prevent the low-insulin alert my endo set at 20 units.

I'd much rather be on the safe side and draw up too much insulin that is "wasted" three days later than realize at the end of the third day that I do not have enough insulin in my pump to last until the next morning's site change and need to do an emergency bedtime site change. I always seem to have bad luck with my cannula being a pain-in-my-butt during nighttime site changes (bending completely and blocking all insulin delivery) that results in me not noticing until I'm at 280 with moderate ketones the next morning.

Sounds like a basic syringe use issue. After you have however much fluid you want in the syringe, draw the plunger further back to suck in some air. Then flick the syringe so the air bubbles consolidate at the top of the syringe. Then deliberately, watching the air bubbles, push the plunger in until you've forced out the air bubbles and can see a clear liquid path to the needle and drops coming out of the needle.

In considering whether you want to stick with a pump, keep in mind it's not just about the mechanics of operating it, it's also about being willing to put in the time to fine-tune your basal rates, bolus ratios, correction factor, etc. If the pump feels like a tool that's going to help you--and many of us feel that way--you may be motivated to deal with those challenges. But if you're not, the pump won't be any different than MDI. And there's no shame in deciding that's the best option for you!