Good work. Yes , appears these machines have been designed with serviceability in mind, they are great to work on.
Cheers
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Cimbali Group Head leak
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An update on the sheared bolt in the G H.
Managed to dismantle the GH and extract from the HX. Friendly VW mechanic down the road extracted the sheared bolt. Rebuilt, replaced gaskets/seals. All is working very well. All completed in 4 hours.
Quite surprised how easy it was to dismantle and rebuild. Crema is even better too....
Many thanks for your advice and support.
Best wishes........
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One for the not good enough files...
We had a VBM DJ come in for service this week. There was no plastic cover on the boiler pressure gauge.
The machine had been serviced by a bloke in country Victoria who "lost" it. Returned the machine to the client with a "Oh yeah. We noticed that it had gone missing. Here's your full-priced invoice."
Fortunately, we had a spare....
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I had a quick look and the rear left bolt has been sheared off - I think but can't prove, the engineer did it. This doesn't sound at all good.Originally posted by MorganGT View Post
I can say that you really don't want to break a bolt off in the head and have to fix it - I have had to do just that when the right hand rear bolt sheared off on a customer's machine as I was removing the collars. The bolt broke off inside the threaded hole, so there was nothing to grab with pliers - I ended up having to remove the whole group head from the machine and carefully drill out the sheared bolt, clean out the threads, refit the head and reseal the HX that it bolts onto. Not a fun job!
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MorganGT, thanks for the response. Hopefully it's not sheared - will check it out tomorrow after work. Fingers crossed hey?!
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There's a distinct possibility that only part of the bolt is missing, and the threaded part is still there, snapped off inside the body of the group head........Originally posted by b9drinker View PostHello Artman, I've checked the group head collar and one of the bolts is missing!! Now I need to find a replacement one that the engineer lost.....
When adjusting the bolts, is there anything I need to be aware of, do they adjust the position of the collar etc?
Those bolts are notoriously easy to shear off if corroded, or if the collar is not aligned exactly with the bolt holes before the bolts are installed. The collar needs to be worked into position so all 3 bolts (lightly lubed with copper antisieze compound) can be screwed in fully just using your fingers, then given a final tighten till snug, not overtight. It's tempting when reassembling a collar to simply push it on enough to get all 3 bolts started in their threads, then tighten them with a spanner and use the tapers to help push the collar into its final spot. Or to push the front of the collar up high enough to get the front bolt started, then use that as a pivot point when levering the back of the collar up into place. Either method puts a lot of side loading on the bolts right at the base of the threaded section where they are at their thinnest, and they will start to crack there. I have worked on a few where the bolts sheared off as I undid them, or as soon as gentle pressure was put on them to tighten them with a spanner, presumably as a result of a previous repairer's efforts damaging them.
I suspect that since this is a very uncommon head design, few repairers really know how to work on them properly, so a lot of them end up a bit damaged. As far as a replacement bolt is concerned, I believe there are actually more than 2 types. Last time I had issues with one of these heads, I decided to carry spare bolts for next time, and went through our scrap machines to collect a few spares. I do remember collecting a couple of each type (10mm bolt head and allen key type), but when comparing them to the bolts on the next Cimbali I did I found there are actually more variations - I can't remember for sure if it was the taper, length or both that varied.
I can say that you really don't want to break a bolt off in the head and have to fix it - I have had to do just that when the right hand rear bolt sheared off on a customer's machine as I was removing the collars. The bolt broke off inside the threaded hole, so there was nothing to grab with pliers - I ended up having to remove the whole group head from the machine and carefully drill out the sheared bolt, clean out the threads, refit the head and reseal the HX that it bolts onto. Not a fun job!
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Many thanks for the reply.
Lovely little machines aren't they. Our pumps out approx 60 to 80 coffees a day ranging from Americanos, lattes and cappuccinos. The steam wand I have looks very similar to the one here:
Coffee Parts | La Cimbali Spare Parts - Steam and Water Inlet Valves
more like the second one. The nozzle is more bullet shaped with a centre hole and three on the very edge of the nozzle.
I don't bother with the auto frother - too fiddly. The wand creates a good foam and that's the main thing.
Occasionally the machine will lose pressure to the point of no steam and no hot water to brew with. The pressure and water level lights come on. Takes a couple or three minutes for it to fire up. This happens about once a day - which can be annoying when mid brewing/steaming.
I've also noticed the steam wand will sometime not have enough pressure and will drop to a faint hiss - does yours do this?
We've let outside "engineers" tinker with it in the past - but after this past experience, that is not going to happen, plus they're expensive. I'm beginning to learn a bit more and am willing to have a go myself.
Apart from that, we love the machine and will pay more attention to it - give it some TLC.
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You have the same machine as me! As an aside I removed the left side auto frother (mine was also missing the plastic bits needed to make it fully functional) and associated solenoid and piping, blanking off the boiler at the corresponding outlet. Makes the machine look cleaner.
Re the bolts , they are listed on coffee parts. There are two versions, the normal bolt style you have and an Allen key variety that looks nicer, which I believe is for the machine versions that do not have the plastic shroud around the group.
Remove all the bolts, remove group and seal. Soak group in caffeto or similar solution. Clean and rinse.
Have a look at the group surfaces where the seal sits (vertical and horizontal). Over time you get a fine layer of black "stuff" sticking to the brass. Scrub and clean it all off.
Take off, soak, clean rinse etc the shower screen while you are at it.
When fitting the collar, just make sure it's nice and snug upwards against the group , rotate it so the collar holes line up with the group holes. Insert bolts and get finger tight. Then tighten progressively each bolt tighter and tighter around a circle until snug.
The bolts have a tapered shank so help centre and locate the group. I applied some food grease to the bolt thread and tapered face as mine were starting to corrode lightly.
It's all very straight forward, I am sure you will work it out when you do it.
What steam tip are you using?
Cheers
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Hello Artman, I've checked the group head collar and one of the bolts is missing!! Now I need to find a replacement one that the engineer lost.....Originally posted by artman View PostHave you checked to make sure the group collar is secured tight up against the group head?
When adjusting the bolts, is there anything I need to be aware of, do they adjust the position of the collar etc?
The front view (2nd photo) shows a distinct lopsidedness to the left of the collar - and that's where the PF is still leaking from. It's all beginning to make sense now.
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You should be able to see if the lugs on the PF are worn, but I would say that would be unlikely.
Have you checked to make sure the group collar is secured tight up against the group head?
With just the conical seal from coffee parts my PF locks in at around 5 o'clock position. The shape/height of the basket lip will also effect the lock in position.
Cheers
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That's the one. Working fine now - just need to change group head seal when it arrives. Can't understand though why I'm having to use a 9mm seal with a .8mm paper gasket - do you think my porter filters need changing?Originally posted by artman View PostNo probs at all, glad I could help.
I presume you mean the pump bypass was stuck? The OPV is what dumps excess pressure when the pump is creating too much pressure.
Cheers
This is what I used before fixing the valve
La Cimbali GROUP SEAL,GROUP GASKET - Detailed item view - Coffee machine spare parts,Espresso coffee machine spare parts Jura spare parts
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No probs at all, glad I could help.
I presume you mean the pump bypass was stuck? The OPV is what dumps excess pressure when the pump is creating too much pressure.
Cheers
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Artman - in my eyes you have the status of a god. The OPV was well and truly stuck. Only took me 15 minutes to remove it, 15 minutes in citric acid (vinegar), 15 minutes back and and Roberts your uncle.
Many thanks mate - so very much appreciated.
Testing it tomorrow proper when we open up tea room, to see whether the GH/PF seal still leaks after I change it. Will keep you updated.
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Many many thanks mate, much appreciated. Shall be having a look later today or tomorrow - that's if my customers don't lynch me for switching the machine off and denying them their coffees!!
Cheers
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