La Marazocco GS3 reservoir tube disconnect

Need help with equipment usage or want to share your latest discovery?

Postby Yuki » Dec 07, 2017, 4:44 am

There is a thread on this site from 2011, but I reckon it's too old, and I cannot find useful information on the web.

The problem is that tiny little connector. It looks like you should be able to pinch and then it expands allowing you to slide the plastic tube off, so the reservoir can be completely cleaned.

I haven't had any luck yet getting any movement. I'm trying not to wreck the thing, too. :lol:

It seems someone has suggested putting a quick disconnect adapter on that, but I have no idea what size to look for, or where.

Another idea was to disconnect near the pump, but that seems like a lot of wear & tear over time.

Ideas greatly appreciated.


Postby Yuki » Dec 07, 2017, 6:29 am

I made another pass at this tonight, but no joy. Clearly a needle nose on that connector expands it, enough that it rotates easily enough, but doesn't move laterally very well at all.

And the tube feels like it's on there with some kind of cement. (It isn't, of course.) I tried rotating it around that sleeve. I could not, even while holding onto the fastener with needle nose. I tried pulling, but it's pretty clear to me the hose will break before that friction gives and it comes off.

So ... I need advice. :)


Postby Moxiechef » Dec 07, 2017, 8:19 am

Post a pic please.



Postby Yuki » replying to Moxiechef » Dec 07, 2017, 4:39 pm


Thanks for offering to take a look.

What you see of course is the intake hose, the U-shaped fitting that goes thru the lid of the reservoir, and the back of the reservoir. There's a clamp that secures the hose to the fitting, which I'm having a lot of trouble with -- actually more trouble with the hose itself than with the clamp, but neither are easy to work with.

In fact, the hose is *so* tight to the fitting right now that I have doubts as to whether the clamp is actually necessary, or just redundant. As I mentioned, I cannot move that hose on that fitting (not even one millimeter, even with the clamp pinched with a needle nose, which opens it up a bit), nor can I rotate the hose on that fitting even slightly. It's so tight it's as if there was contact cement or something that was applied, but of course I'm nearly positive that's not the case.

It seems according to the manual I should remove this (decouple) for periodic cleaning of the reservoir. I'm sure eventually there would be algae otherwise.

Yet, as you can see, that clamp looks tight. It either produced an impression on that hose, or else the hose is designed that way, and there is some indentation on the metal fitting itself that it "seats" on. My eyes are not good enough to see for sure.

I've worked that clamp back a bit from its original position in this picture (did that last night). But I've gone no farther, because the effort in moving it just that far was considerable, and I've little (actually almost zero) confidence that I could get that clamp back on if I moved it off either the fitting (in the direction I've moved it so far), or off the hose entirely (going the other direction). Particularly, if I moved it off of the hose completely, I doubt I could ever get it back onto the hose, but really in either case.

You can see the constriction of the section of hose not attached to the fitting. I'm not even sure if I decoupled this I could get the hose back onto the fitting. That looks *really* tight. It looks like it was no easy job to get that hose onto that fitting in the first place.

The clamp has been in this position overnight now, and there is still quite a dent in that hose where it originally was, so there has been no "rebound" in the plastic, and I don't know if that dent is by design or was caused by the clamp. I would have expected a bit of "rebound", and maybe some indentation where the clamp is currently positioned, after 12 hours. But no.

The hose is *just* long enough for me to clear the chassis with the reservoir, which would allow me to remove all the lid screws (and then the lid itself), which would allow me to completely clean the body of the reservoir (the coupling would remain, and so I'd have to do the best I could cleaning the lid with it attached). Seems awkward to me, but I have lifted that U-shaped intake fitting, and it does lift up.

(The condensation you see on the lid of the reservoir, giving it a rather translucent appearance, is because I've just got the machine up to temperature on a rather cold morning. It's normally not there, and this view would be clear as glass.)

The fitting seems not able to be pulled out of the reservoir (as if you were going to simply take it out without decoupling from the hose). I suppose when they assemble it they put the fitting (somehow) up thru the bottom of the lid, and then couple them.

My goodness, this seems a design that could be easily improved upon, :? as this would be a biweekly or at the very least a monthly cleaning necessity.

Thanks again.


Postby Moxiechef » Dec 07, 2017, 8:02 pm

If there is enough slack in the hose, you can cut it right at the end of the metal and start over. If so, then take a knife and slice off the part stuck on the metal pipe.


Postby Yuki » replying to Moxiechef » Dec 07, 2017, 9:41 pm

There's really not enough slack for that. If it were a semi-annual, or annual thing, perhaps, and I'd just be willing to replace that hose completely now and then. But this is a "frequent" thing, I would say weekly, or bi-weekly, at the very least monthly. Cutting off sections of hose each time would quickly have that hose too short.

Moreover, that hose is on *tight*. You can see from the photo it's quite "stretched open" over that fitting. It seems the exterior gauge on that hose might be the same as the interior gauge of that fitting. (Makes for a "snug" connection, which is a good thing where water is involved, but not such a good thing if it's a connection that needs frequent disconnection--reconnection.) I could perhaps force (stretch the opening of) the hose back onto the fitting after a cut, but I doubt I'd be able to get the clamp back over on top, then. The entire operation would be a task, for sure.

I'm talking to someone at LM USA about this, too.

I also made some design suggestions.

1) The connector is much too tight for a non-pressurized (I'm assuming) water connection, and especially one that needs 'frequent' disconnection/reconnection for cleaning purposes.

2) I'd lose that metal fitting. I'd replace it with a fairly stiff pre-formed plastic tube that had the same gauge as the hose's. Then I'd use a "quick connect/disconnect" hose coupling for the connector.

3) Maybe best, I'd skip a fitting there at all. I'd run the hose directly thru the reservoir lid as one piece. I'm sure the angle is a bit of a problem for a fairly stiff hose, the reason they've gone to metal there. But I'm sure a solution can be devised that would work. The hose intake would still need to be near the bottom of the reservoir, as is the case with that metal fitting. But it does not need to be *immediately* below the hole in the reservoir lid as it is now.

Just angle the cut in the lid a bit, and run the hose in at enough of an angle not to crimp it (the hose would need to be a bit longer in this case, with an angled hole). You could still have some kind of clip on device at the bottom of the reservoir, as they do for the metal fitting, to hold the hose in place during use, but still allow a user to pull the hose up through the hole so the entire apparatus could be easily cleaned. If the hose can be pulled directly thru the lid hole, it would be possible to fasten the hose to any connector at the bottom of the reservoir (holding the lid well aloft), and then reattach the lid. Likewise for disassembly. Unscrew the lid, and hold it aloft while removing the end of the hose from whatever clip at the bottom of the reservoir it is secured to, and then pull the hose up right through the lid. Voila.

4) Much easier periodic maintenance for users, and I suspect maybe even cheaper production cost, plastic versus metal.


Postby Moxiechef » Dec 07, 2017, 9:48 pm

Good luck. The LM folks are good. Let us know the outcome.


Postby RockyIII » Dec 07, 2017, 10:20 pm

On my Linea Mini, I added a Nalgene 6150-0010 HDPE quick disconnect tubing connector in the line right behind the reservoir. It worked well and made removing the reservoir for cleaning very easy. I don't know if the same size would work on the GS3.



Postby Yuki » replying to RockyIII » Dec 07, 2017, 11:35 pm

I might try it. Ouch. About 125 bucks for a pack of 12 on Amazon. Clearly I don't need 12 of them. :)

Key question: Is the Mini plastic hose to metal fitting, like the GS3? (Similar at all to my photo?) Imagine maybe yes, as manufacturers love as much redundant parts as they can get. But gonna ask.


Postby Yuki » Dec 07, 2017, 11:41 pm

Moxiechef wrote:Good luck. The LM folks are good. Let us know the outcome.

My man at LM USA says (after seeing the photo and really getting it):

"I see what you mean. Yes, the manual is overly optimistic about how the reservoir should be cleaned. We recommend not removing it, and only wiping it out with a damp clean towel. This will keep your reservoir clean, chemical cleaners out of your boiler, and less wear and tear on the reservoir components.

Please feel free to give me a call tomorrow if you would like to chat about it."

So, "overly optimistic" is not good, but truthful. It's certainly my experience. I think I'll try this "wipe it down" bit for a while, and see how it goes. But I like RockyIII's idea about the Nalgene 6150-0010 HDPE Quick Disconnect Tubing Connector, 1/4"-5/16" Tubing ID, 2-1/2" Length, too.

If I was sure that was a solution for a GS3, I might pop for 12 of them, even though in theory I'd only ever need one or two.