# VBM Leak



## olivermleach (May 25, 2019)

Thought I would start a new thread for this fix job. Recently bought a domobar super hx and have had some issues, got it working, only remaining problem is a cold puddoe of water forms under the machine over a period of time, especially when machine is idle (probably as this is a longer period of time). There was some leaking from the valve on previous inspection so I suspect this is the issue, but am wondering if anyone has any additional ideas for possible causes? Both valves seem in good condition when inspected, so I'm not sure if simply replacing one or the other will help.


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## El carajillo (Mar 16, 2013)

Providing the fill probe is clean and the machine is not over filling the valves should not be surrounded by water and leaking.

Note the position of the puddle, then relate to items in / on the machine eg pipe joints / connections/ solenoid etc.


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## Debbie (Jun 24, 2012)

Found this old thread via a search.
My VBM Junior DB made a funny clunking noise this morning, with steam coming from the lid, and I've noticed a leak.

It's currently switched off and cooling down.

What should I be looking for when it's cool: is there anything I can do or will it need a professional to look at it?


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## DavecUK (Aug 6, 2013)

It sounds as if the safety valve *may* have opened do to excess pressure in the service boiler. This *might* be because the pressurestat is not working correctly, *possibly* due to limescale. The normal sollution would be to replace the pressurestat.

Without knowing the age of machine, type of water used, it's always difficult to diagnose problems.


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## Debbie (Jun 24, 2012)

It's 2 years old, always filled with Volvic. Not serviced professionally yet.


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## DavecUK (Aug 6, 2013)

When the safety valve opens, it's normally a pop/hissing sound and a cloud of steam....not usually a clunk, which is the only bit confusing me.

Best take the top lid off (probably 4 screws) and have a look in the top, take a photo and upload it as that can be helpful. Usually a failing stat shows no signs but perhaps a wire came off or some other problem.

P.S. If it was a gentle hiss and a small amount of steam, it could be the vacuum breaker, a photo will help because if there is a vent tube on the vacuum breaker leading to the drip tray or tank, then it can't be that (unless the tube fell off).


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## Debbie (Jun 24, 2012)

Will try that, thanks.


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## olivermleach (May 25, 2019)

Resurrecting this topic in the hope of some technical support from the kind people of this forum.

I kind of sat on the issues with this machine. Got it working and there was then just a slow leak to one side, minimal pooling, and I found strangely that if I just removed the pipe connecting from the water reservoir into the pump then it leaked minimally when idle.

Recently my espressos have gone downhill and I have noticed some issues with brew pressure. I'm pretty sure the pump is needing replaced. I have cleaned and descale the machine with marginal improvement in results - espresso are lacking flavour, reduced crema and general sub-standard shots.

The pressure needle is weirdly fast to rise then quivers as if the pump is struggling. With a blind disc the pump can't get up to 10 bar without at least half a minute to get there and I no longer hear that lovely 'pre-infusion' sound I used to get as the high pressure hits the puck.

I will update with some photos but would appreciate some advice on the pump replacement. I've order an Ulka EX5 and some silicone tubing.

When I took the machine apart I found the leak - on the feed tube into the ulka pump where a cable tie is sitting - evidently not tight enough.

I have unscrewed the screws holding the black feet at either end of the pump. I just need help dismantling and rebuilding the tubing and parts on the exit side of the pump. And are cable ties at each tubing juncture a good idea for watertight seals? I've seen previous posts calling all this a "15 minute job" - maybe for someone experienced with all the right tools and parts. But if I've learned anything for fixing bikes it's that even superficially easy jobs can be done badly and full of minor pitfalls.

Cheers,

Oli


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## olivermleach (May 25, 2019)




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## olivermleach (May 25, 2019)




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## olivermleach (May 25, 2019)




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## olivermleach (May 25, 2019)

Apologies for the slightly blurry last photo. I took a higher res close up but was over max file size.

As you can see I have easily removed the left-hand side and unscrewed the feet of the supporting black rubber supports at each end. Now I'm left with the soft plastic ulka connector, a brass connector and the tube leading to the ? Overpressure valve?

Not sure what order to disconnect things in.


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## DavecUK (Aug 6, 2013)

In the last photo, the middle tube is a deaerator, you don't really need the whole deaerator thing, see if you can remove it.


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## olivermleach (May 25, 2019)

That connector has a tube running to the back of the machine, to another split connector, one of which then goes back to the water reservoir. Not sure what I would do with the piece of tubing if I removed the deaerator.


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## olivermleach (May 25, 2019)

So I've actually managed to get the pump out, but would appreciate advice as to whether cable ties are the way to go for securing the piping back on.

I'm surprised the 2008 Ulka was still turning on...


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## olivermleach (May 25, 2019)

Actually this did end up being straightforward. I used cable ties to tighten the silicone tubing at connection points and the new pump is working well.


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