# Leaking piston



## rob177palmer (Feb 14, 2017)

So this has started happening today.

Constant dripping from where the top and bottom parts of the group connect. Changes to a flood when i cock the lever!

Have tried loosening and nipping up the four Allen bolts, but hasn't improved things.

Do I need to strip down and replace the seals?

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## 4515 (Jan 30, 2013)

I remember seeing a thread that mentioned this about a month ago. Cant remember the fix though so that's no help to you at all !


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## rob177palmer (Feb 14, 2017)

Thanks for confirming this problem is definitely a thing though!!

Any idea who helped diagnose?

Having researched a bit, I can see @The Systemic Kid has a fair bit of knowledge on piston seals!!??


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## El carajillo (Mar 16, 2013)

Not relevant to problem.


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## The Systemic Kid (Nov 23, 2012)

If the Veloce's group is same as that fitted to Bosco and Londinium, guess it's a piston seal fail. There isn't any seal where the group bolts to the head. Remove the four hex bolts and then remove the piston/spring assembly and check the piston seals. Bella barista sell them.


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## The Systemic Kid (Nov 23, 2012)

@rob177palmer - when removing the hex bolts do so diagonally. Undo any bolt a small amount and then go to its diagonal opposite. The group is brass and it's important that it doesn't get warped - diagonal undoing will ensure you don't cause any problems. Make sure you are undoing, i.e. turning anti-clockwise - it appears as if you are tightening because the bolt is upside down. When re-tightening the bolts - repeat as above, i.e. tighten bit at a time for each bolt in diagonal rotation. *Don't over-tighten* or you will strip the thread - easy to do as it's brass. Remember, it's the piston seals that keep the water in the chamber - not the bolts which is why there isn't a gasket between the piston/spring assembly and the group head.


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## rob177palmer (Feb 14, 2017)

Thanks Patrick. And noted on the overtorquing

I will get on to B.B. on Monday and get the replacements ordered. Till then I presume there is no "make do" mend I can perform?

Wish I had foreseen this - I was planning on shipping over the Cafelat gasket set - presumably these still aren't available for sale in UK?


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## The Systemic Kid (Nov 23, 2012)

How old are the seals in your Veloce? When they're passed their sell by, they become brittle which is why you're seeing water escaping where the group is bolted. You'll be losing a fair amount of pressure so don't recommend using the machine until the seals have been replaced.

I fitted a set of Cafelat to my previous LI and was pleased with the results. That said, other users reported some problems. Think Cafelat have made some subtle changes to resolve this.


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## rob177palmer (Feb 14, 2017)

Thought I would open her up to have a look....obviously the brew chamber was full of water....didn't think of that - glad the acaia scales are waterproof!!


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## rob177palmer (Feb 14, 2017)

Interestingly it smells a little rank inside the brew chamber. I haven't whipped he shower screen off the clean behind yet, so looks like I should have done this within the last 3 weeks of brewing


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## rob177palmer (Feb 14, 2017)

Is it normal for the white plastic to be cracked?









No obvious obvious cracking of the black seals, but all new to me!


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## coffeechap (Apr 5, 2012)

Yes perfectly normal


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## The Systemic Kid (Nov 23, 2012)

It isn't cracked - has to be split so it can fit over piston barrel. Be careful removing it to avoid breaking.


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## rob177palmer (Feb 14, 2017)

Thank you kindly.

Have found Systemic's piston seal changing lecture from Rave in 2016 so will watch that to get the hints on hanging these out


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## The Systemic Kid (Nov 23, 2012)

When you prize off the seals, they might feel quite stiff, i.e. have lost their elasticity which is why they are letting water get past in the piston chamber.


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## coffeechap (Apr 5, 2012)

Seals look wrongly configured, top and middle look right but the bottom looks upside down it should be groove down and looks groove up


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## drude (Apr 22, 2013)

working dog said:


> I remember seeing a thread that mentioned this about a month ago. Cant remember the fix though so that's no help to you at all !


This happened to my L1 a little while ago - might have been my thread you saw. Problem solved by putting new seals on


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## Stanic (Dec 12, 2015)

time for the cafelat seals


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## Syenitic (Dec 1, 2013)

Did you not just buy this machine from BB in the last fortnight? Amazed it has failed so soon, and would presume they would have provided some form of warranty?


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## rob177palmer (Feb 14, 2017)

coffeechap said:


> Seals look wrongly configured, top and middle look right but the bottom looks upside down it should be groove down and looks groove up


Is this the groove you mean?


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## rob177palmer (Feb 14, 2017)

Yes - 3 weeks old so hopefully BB will sort it for me. Sadly don't think the stock cafelat and I will need them ASAP next week so doubt I'm going to be able to get them shipped to me in time!


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## coffeechap (Apr 5, 2012)

Speak to B.B if they haven't got them let me know


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## Stanic (Dec 12, 2015)

a good video on changing the seals and their orientation


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## rob177palmer (Feb 14, 2017)

BB have kindly sent me replacement standard seals - 24 hours between reporting the issue and the parts arriving so pretty pleased with that.

Didn't realise seals could go so catastrophically on a lever, so will order some spare cafelat piston seals and a couple of group gaskets as the standard rubber one seems to strongly resist locking the PF.

Aiming to install tomorrow so will report back once everything up and running.

Cheers for the help so far


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## Tewdric (Apr 20, 2014)

Have you got the right grease Rob? I work in Bristol and have done this job a few times now so give me a shout if you get stuck. My initial thought was wrongly installed seals - they should be "down up down" with respect to groove orientation - I think yours are right but difficult to say with the bottom one which looks a bit squished. Old stock lever mech maybe? New seals should see you right though.

Do watch Patrick's video, all you need to know!


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## rob177palmer (Feb 14, 2017)

So happily the old seals were installed correctly but, compared to the new ones, were clearly squashed and degraded - even though they had seen little use I guess they have been constrained in the brew chamber for a couple of years. The brew chamber was perfect condition as was the brew group, but they were clearly the original seals as no evidence of previous ones being cut off.

Thankfully B.B. sent me a small pot of the right grease. I have followed Patrick's video and the machine is now reassembled and heating up - time will tell if it is fixed but seems very positive.

Here is the finished job - the seals splay out much more than the old ones:










I did come up with a very helpful tool to help side on the seals, which might help others - in place of Patrick's "two bits of sturdy wire" I trimmed the sides off a takeaway curry container (from Ahmed's Curry Cafe, if anyone would like to replicate completely!!) and the resultant flat but of plastic was almost the perfect size and the gaskets just slid straight on.










In Patrick's vid there was an American (?) bloke asking questions and he suggested he warmed the seals in water. I did this and dried them well and that really helped also.

So now the machine is ticking away nicely in the corner again.


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## christos_geo (Feb 9, 2016)

There was no white plastic ring in your finished product photo! I take it you did fit it right?!


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## Stanic (Dec 12, 2015)

lovely! I am thinking, this might also increase the brew pressure slightly compared to the old worn ones


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## rob177palmer (Feb 14, 2017)

christos_geo said:


> There was no white plastic ring in your finished product photo! I take it you did fit it right?!


Haha - yes - I am 99.9% certain that I did







I just took the photo too early in the process and forgot to take a later one. I must confess I had to rack my brain when posting as to whether I could remember a clean white ring being installed, but I am fairly sure I can and it doesn't seem to be in the bin!!


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## rob177palmer (Feb 14, 2017)

Stanic said:


> lovely! I am thinking, this might also increase the brew pressure slightly compared to the old worn ones


I am hoping so - in the days before the seals went I noticed my max shot out volume was down to 30g, which didn't worry me as current running 15g in 29g out but now I know to read the signs of impending doom!


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## 4515 (Jan 30, 2013)

Huge difference in the old and new seals. I wonder if the old seals had stuck to the wall of the group and damaged an edge

You should feel a difference in the lever when you pull the next shot


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## rob177palmer (Feb 14, 2017)

Working like a charm! Incredibly easy service.

Lever now grabs a little sooner (I was expecting a greater change) but output volume is massively increased. First shot was too coarse so I just let it run:










This opens me up to experimenting with much longer ratios and, TBH this 1:3 shot tasted far more balanced that the 1:sub-2 i had been playing around with for these beans.


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## Stanic (Dec 12, 2015)

great!

guess that if using a triple (20-25g) basket you wouldn't have to remove the cup, making it effectively a volumetric machine


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## 4515 (Jan 30, 2013)

I find that the bite point doesn't change that much with old and new seals, more the feel of the bite point is smoother with new seals.

Edit : but if you have more water now, the bite point should be lower unless water was escaping to the top of the piston ... maybe ?


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## iroko (Nov 9, 2012)

Glad you have sorted It out.


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## Greydad (Feb 25, 2018)

Great read, glad you got it sorted, well impressed with the knowledge and support from people on this forum it's a pleasure to see so much expertise so informally and freely given. Props to B.B. too for their service


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