# Disassembling a Fluid-o-tech rotary pump head



## John Yossarian (Feb 2, 2016)

Hello All,

I have replaced my original pump head (50 l/h capacity) with a brand new 200 l/h and after that another one at 150 l/h.

In doing that I have lost the soft infusion, which is linked with a camera in the brew head but works only if the pump were 50 l/h. I still have got my old pump head and was curious whether I could repair it, given that I have got one extra sitting on the shelf at the moment.

There is a screw cap No. 24 in the picture, that seem to need a special tool to unscrew it.

Can you advise on how to tackle with this issue?

Can you also share (if you have done it) whether it is worth it?

Thank you in advance!

Cheers,

John


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## El carajillo (Mar 16, 2013)

According to the list item 24 is a label, probably stuck on ?


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## John Yossarian (Feb 2, 2016)

El carajillo said:


> According to the list item 24 is a label, probably stuck on ?


 I am sorry. 24 was meant to be 12. The label is already off.

There are two holes axisymmetric at about 2.5 cm from each other. I suspect it calls for a special tool.


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## El carajillo (Mar 16, 2013)

Looks like you need a "caliper face spanner" You can make these using two strips of metal fixed together at one end with a bolt. The free ends fix two pins the diameter of the holes in the plate :good:


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## DavecUK (Aug 6, 2013)

You might find it hard to get the spares required for the rebuild. Usually it's better just to buy another one.


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## John Yossarian (Feb 2, 2016)

Thanks Dave,

I was hoping to use some of the spare pump head that sits on the shelf! As it was causing pressure rise in the brew line upon heating I am hopeful it might be some o-ring causing it.

@El carajillo I will try and see what I can do.


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## DavecUK (Aug 6, 2013)

John Yossarian said:


> Thanks Dave,
> 
> I was hoping to use some of the spare pump head that sits on the shelf! As it was causing pressure rise in the brew line upon heating I am hopeful it might be some o-ring causing it.
> 
> @El carajillo I will try and see what I can do.


 I would Imagine the one way valve after the pump in the brew circuit might be letting back. Elaborate more on what was happening and have the new pumps stopped it?

https://www.fluidotech.it/en/products/technologies/rotary-vane-pumps/co-mo-50-200-series/

You need the CO50....if indeed the pump is at fault.

All the ebay cheapies will be for larger multi group espresso machines and have far too high a flow rate....as you have found.

P.S. A rotary pump has no valve that only allows water to move one way e.g. inlet to outlet.


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## NewboyUK (Jul 14, 2018)

I second this - what was actually happening and what machine was it?

On machines I work on there is a one way valve on either the manifold or the outlet of the pump....


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## John Yossarian (Feb 2, 2016)

A bit of progress has been made.

I have managed to find a caliper type key/spanner as per @El carajillo advice and unscrewed the threaded cap. Underneath I found the stainless steel shaped disk (11) that fell freely and the O-Ring (10).

The inner side of the O-Ring was all white, I assumed lime-scale but it is also very evenly spread around the Front Flange (7) and looks as if purposefully placed there.

I cannot see any screw/nut that should keep everything together but yet I do not dare to start pushing it out not to break anything. The white stuff (that logically should be lime-scale) can be (?) some kind of glue/insulation?

Can you please advise whether it is safe to continue trying to get the innards out by simply knocking the brass body against a vice for xample? Any other ways?

Cheers,

John


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## El carajillo (Mar 16, 2013)

Take a look online for Fuid-o-Tech rotary vane pumps manual =exploded view of pumps and parts description.

Take it apart in a super clean area with space to lay out parts. The vanes and springs are delicate and need to be VERY carefully assembled.

Keep everything clean including your hands. Good luck.


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## John Yossarian (Feb 2, 2016)

Thanks El Carajillo!


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