La Cimbali M29 overhaul project - Page 2

Need help with equipment usage or want to share your latest discovery?
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trumz (original poster)
Posts: 359
Joined: 10 years ago

#11: Post by trumz (original poster) »

Well, she's plumbed in but not out yet. Still waiting on the drain elbow. I had leaks around the group heads and around the gasket. I didn't think to adjust the pressure down on the brand new pump. Turned it down until there were no leaks plus a few more revolutions. Would be nice to have a pf gauge...



First shot at unkown pressure.

thymaster
Posts: 17
Joined: 9 years ago

#12: Post by thymaster »

Hi there,

I am just about to start the exact same project as you just did. As I am getting started do you have any tips on taking it apart and cleaning it? What type of cleaning supplies did you use? Was anything tricky to get out and clean?

Thanks a ton for your help. Im looking forward to hearing how yours turns out!

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trumz (original poster)
Posts: 359
Joined: 10 years ago

#13: Post by trumz (original poster) replying to thymaster »

Hey, this was my first time playing with an espresso machine and it was pretty straight forward. Pretty easy to work on these, lots of room.
It depends on the condition of yours, but A full tear down is probably a good idea. Soak all the piping in citric acid and dissaemble and clean all valves. Replace all rubber o-rings and gaskets.
Take your time and, like many have said to me, take lots of pictures. I took over 100 while dissasembly and they have helpd a lot when putting everything back together.
You can PM me if you want to ask anything spcific to the M29 or start your own thread and I'll be happy to try to help. Good luck!

thymaster
Posts: 17
Joined: 9 years ago

#14: Post by thymaster »

Thanks!

Did you submerge the boiler in citric acid? If so how much did you use? When cleaning the pipes how long did you soak them?

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trumz (original poster)
Posts: 359
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#15: Post by trumz (original poster) »

Yes I submered the whole boiler in citric acid. I can't remember for exactly how long but maybe it was an overnight soak because some of the nickel plating came off in one area, not a big deal I don't think.

All the copper piping was soaked for 4-7 hours. Some peices I soaked a second time. The citric acid and water ratio I used was very roughly 100g to 2.5L of boiling water.

Paul Pratt's website was helpfull. http://www.espresso-restorations.com/Index2.html

Mokko
Posts: 60
Joined: 9 years ago

#16: Post by Mokko »

I am far from an expert on a la Cimbali. I have an m29 Selectorn DT2 that gets turned on each weekend morning for a few shots. Every morning when I turn the power switch the first click, the auto fill kicks in and adds water to the boiler, then once the red low water light goes out I go the second click and add power to the heating element. There are some Saturday's that I forget to shut the machine off after the morning shots and at some point in the day I hear the auto fill kick in. The Selectron also has a manual fill knob to add water to the boiler that i will use if I want less noise in the morning as the machine warms up.
Not sure if that answers your question or helps, but wanted to chime in.

Mokko
Posts: 60
Joined: 9 years ago

#17: Post by Mokko »

Kyle,
Have you thought about doing some of the aftermarket mods to your machine that are talked about on here? The 2 mods that have me interested are the "on-delay" relay wired into the pump. The logic behind this is you can delay the build up of pressure from the rotary pump (6 seconds is about optimal from what I read) and get pre-infusion on your shots. The advantage is not necessarily better tasting shots, but fewer throw away shot from channeling.
The second mod is to install a PID on the heat exchanger. The advantage to this is tighter temperature control than the P-stat delivers, and an easier way to adjust boiler temperature than small turns on the P-stat.
Others have also I stalled a temperature probe through the screw hole on the front of the group head. This capability seems to give you temperatures to evaluate your shot profile, or more data to work towards the perfect shot.
Lots of great information on this site, but I wonder if it is making me an espresso hypochondriac.

thymaster
Posts: 17
Joined: 9 years ago

#18: Post by thymaster »

I ended up getting the power situation figured out. I have everything all plumbed in and hooked back up since my overhaul. I am now stuck in three spots (all really close to each other).



- Between the heating rods and boiler it is leaking. Do you know what size gasket you used or what else I could try to remedy the situation?
- Do you recognize the ground wire in the pic? I cant remember where it goes.
- Do you know where the plastic clip with the brown wire goes?

Thanks
Aaron

Mokko
Posts: 60
Joined: 9 years ago

#19: Post by Mokko »

Aaron,
The brown wire with the plastic tip goes on the end of the probe that is above the heating element (I think it is the water level probe). My machine had a liquid gasket between the heating element and the boiler. It was attached so well that I left the heating element on the end of the boiler cap when I did my takedown. With mine it was deep red in color, maybe an auto parts store will have a high temp liquid gasket. As for the yellow with green strip ground wire. I have one just like it with no home. On the opposite side plate of the machine both the yellow and yellow with green stripe are grounded to the outer panel. Mine is still loose and has a quick disconnect end vice the round end like yours. I can take a picture tomorrow if you need one, or Kyle does not chime in. Hope this helps.

noidea
Posts: 10
Joined: 10 years ago

#20: Post by noidea »

trumz wrote: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.
Hi trumz

Do you happen to have any photos of the group head / heat exchanger gaskets and seals and how they are installed? I'm rebuilding an old La Cimbali Junior and it had a mixture of Teflon gaskets and black O-rings installed but from the way they were leaking I don't think it was correct.
Cheers