La Cimbali M29 overhaul project

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#1: Post by trumz »

Hei everyone!
I have recently purchased a 2006 Cimbali M29 Select from an ex coffeeshop and have started disasembly to clean everything up and to get a better idea of the condition of the thing. When I plugged it in, the pump ran and sucked a few liters from a bucket but it didn't sound healthy.

I was only getting very little water from the first group and nothing from the second. No heat either. At that point i decided that I would have to completely strip the machine.

I've gotten both groups, boiler and all of the piping off and soaking in citric acid.

1. Apon further investigation on the pump, i found that the piece directly under the manual adjustment spring/screw is busted. Can these be baught and replaced?
Here is a pic:

3. How does this heating element look? Can I submerge the whole thing in citric acid?

I'm sure I'll have a bunch more questions but I think thats it for now. Thanks a lot, your help is much apreciated!


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#2: Post by trumz »

Well I'm almost down to the frame. Only electrical left. A wee bit nervous taking that completely out but it's probably a must. No rust on the frame though.

Still not sure if my pump can be salvaged or if I have to buy a new one. Any ideas?

Take a look at the stuff that I found in the boiler :shock:


#3: Post by yanonanite »


In answer to your questions,

1. You should be able to find that piece somewhere if you look hard enough, but many people just order new pumps.

2. The heat exchangers will be fine as long as they have not ruptured.

3. As long as the element shows the right resistance for its rating it will be fine. That one looks to be in relatively decent shape. DO NOT put the whole thing in citric acid. If you want to use acid on it, just hang it into a bucket or something so that the element side is submerged but the side with the wire posts is dry.

Good luck with your project! I'm working on an M29 right now myself.

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#4: Post by trumz »

Hei! Thanks for the reply!

I really can't find that part for the pump anywhere. The diagrams that I found don't even show that peice. I emailed Procon and they said that the pump was too old to rebuild... :roll: I guess a new pump is the way to go then.

Good new about the HX's. I hope they will hold up when HOT.

I did submerge the whole heating element in citric acid, so I hope it'll still work. It's nice and clean now. Should be ok.

How is your M29 coming along? Would it be possible to get a picture od the plumbing on the right side of the machine? Mine has had a previous repair that I'd like straightend out. I think I may be missing a small piece of pipe.


#5: Post by yanonanite »


Yeah, rebuilding old pumps sometimes requires a pile of salvaged pumps to work from.

The reason I never put the electrical posts of heating elements in acid is that sometimes the acid can eat through the seals and ruin the elements. This probably won't happen unless you let it soak for several days though.

The one I'm working on is ready to be put back together, but it's slow going figuring out where all the washers go and making sure I don't miss anything.. I didn't take good pictures before I took it apart and that was about 5 weeks ago.. :? Overconfidence is a problem when it's hard to find good parts breakdowns. I'll send you a picture once I've got all the pipes back on that side in the next day or two.

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#6: Post by trumz »

If you need any pictures, let me know. I took over 100 pics and I could email you a bunch.
I've got a pump, new shower screens and various gaskets on their way. I also got the inside all whiped down And ready for reinstalation. Heating element is super clean as is the boiler and HX's.
I still need portafilters... And the Fnnish Cimbali rep is helping me out a lot of informayion and parts. Really nice guy.

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#7: Post by trumz »

I received group solenoid o-rings, group head gaskets, etc. Waiting for a pump, heating element gasket and heat exchanger gaskets. I also insulated the 5L boiler.

I have another question. There is no ground wire going to the water mixer solenoid. Do I need to connect one? I would also appreciate tips on what to do when I first plug the machine in for the first time after a rebuild. Anyone with experience want to chime in? Trying to avoid any catastrophes as this is my first time!

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#8: Post by trumz »

I hooked her up to water and found a leak on a pipe going to the HX. Turns out that pipe has a crack in it! So I'm on hold for now until I get a replacement. So far so good though.
I've replaced;
shower screens x2
HX gaskets x4
three-way solenoid washers x4
group head gaskets x2
heating element gasket
new portafilters
This is what it looks like now.

I'm missing one of the small grill that sit a top the drip tray. Anyone know where I can buy one??

Chad C.

#9: Post by Chad C. »

Nice work. These are very nice machines. I've worked on a handful of La Cimbali machines, and I just finished the resurrection of Cimbali two group lever machine. Having serviced commercial machines for 15 years, I believe that La Cimbali has the best build quality of any of the heat exchanger machines. They really can last forever. Their proprietary pressurestat is a bit fiddly, but it's a decent design. Their proprietary auto-fill system is excellent, and robust in comparison to a Sirai style electronic system.

If your machine went through at least one winter in Finland in sub-freezing temps and doesn't have any ruptured metal pieces, that's a testament to the quality of the machine. Keep it forever!

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#10: Post by trumz »

Thanks for the kind words Chad. It was my first time doing anything like this and this is my first machine. The previous owner said it was stored in a barn... with water inside... i'm lucky the HXs didn't burst.

I just got her up and running but she's running a pretty high boiler pressure. I have the thermostat adjustment nut almost at the very top of the shaft and can't adjust it down very much more. Boiler pressure reads around 1.5 bar. It drops to 1.45 and at that point the heating element kicks in to bring pressure to 1.53 bar. Any help would be great! Cheers.

Edit: Turns out my boiler pressure gauge was reading 1.05 bar when cold. I ended up taking the needle off and repositioning it at the zero mark. And now, when the machine is hot it reads around 1 bar. I know now that my gauge probably isn't 100% accurate but it should be pretty close. Not really worth the price of a new Cimbali gauge...