Medtronic 770G and 1.8 mL Reservoirs?

Hi all,

I am upgrading to a new 770G soon and I have a ton of 1.8 mL reservoirs stock piled. The rep was very nice and proactively told me there is a “hack” to use the 1.8 mL in the 770G.

Has anybody had any experience with this? Maybe fill me in on how it works?

Thank you!

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They work just fine, no hack needed!

If medtronic told me today was Tuesday I would check a calendar

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Could you explain the steps in using the 1.8 mL in the 770G?

Same steps as the 3.0

For what it’s worth this person says they will work fine. Here’s the quote:

· 3y

You know when you go to fill the tubing with insulin? Your pump will just keep pushing until it hits the reservoir and you’re finished. Same procedure for using the 3ml just with a shorter reservoir. It will twist and lock in the same way. Try it. Your pump just won’t read you as having a full reservoir.

Anyway, it ought to be worth a try, Luis

@Rphil2 may know.

From Medtronic documentation it seems officially only 3.0 reservoirs used on 770.

I recently switched to Tandem, after 25+ years using Medtronic pumps, so I have leftover 1.8 reservoirs too.

Hope you find answer.

What possible hack could there be?

Physically altering the cylinder or maybe a software change?


the 1.8 cylinders work

Thanks for everyone’s replies.

I also assumed that you just “primed” the reservoir like normal and it would just keep spinning until it reached the threaded plunger of the 1.8 mL reservoir (showing a partially filled pump).

My rep made some comment about a “hack” and using “the end of a pen” or something? Who knows.

But, at least I have real world replies that show I can keep using my stockpile of 1.8’s.

Thanks again!

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I have never used 1.8 reservoirs so I am not a good source. However as others have said I do not think it ill be an issue. The pump will rewind to accommodate the 3ml reservoir and then you will advance it until it meets resistance. From there it should behave normally.

The down side will be it will take a bit more time to get your pump primed. The upside, you will save insulin.

It seems like a more than even tradeoff. Oh and I found the reservoirs in the medtronic diabetes shop.

so at this point at least even Medtronic is selling them.


Note: I am a Medtronic ambassador. My opinions are my own. They did not pay me to say nice things. OK, they sent me a shirt and a cup but even I am more expensive than that.


I am using the 770 pump and when I ordered my pump supplies they didn’t have the 1.8ml resevoir in stock so I ordered the 3ml instead. So I shouldn’t have any problems filling it and loading it in my pump, right? Someone said it will take longer to prime, why is that?

I use a 630, and the 1.8 reservoirs (although CCS sent me a box of 3.0 reservoirs by mistake). When you put the filled reservoirs in the pump, yoy then have to “load” the reservoir. The pump will push up until it meets resistance. So, you can use 1.8 reservoirs or even 3.0 reservoirs that you only fill to 1.8. Once you’ve finished loading the reservoirs, the rest is the same procedure as on the paradigm models.

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Similar for me when my medt 523 failed under warranty and they sent 723 as replacement. I used the 1.8 reservoirs in the 723, no problem.

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