Conti Empress group seals not wide enough

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Paolo

#1: Post by Paolo »

I hope that someone can help...

I had a Conti Empress group re-chromed recently. The chrome plater did a great job except he didn't chrome under the group, where the group seal locates, making this channel (due to no chrome being there) a little bit wider and deeper than it should be.

As a result, a normal Conti group seal allows a dribble of water to seep through under extraction. I have to tighten the group handle with more pressure than I should...and often there is a dribble anyway. It is extremely annoying... :cry:

It is like the coffee version of water torture! It annoys me just a little bit more each time.

I was thinking of putting a layer of silicone plumbers' tape in the channel and then inserting the seal into the taped channel but there has to be a better way.

Has anyone had a similar experience and beaten it?

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Jeff
Team HB

#2: Post by Jeff »

No personal experience, but Grouphead gasket for Conti Prestina as well as the list at Conti Empress Replacement Parts List may help

"Siebträgerdichtung Conti" is, I believe what we call a group gasket
https://www.tse.at/shop/product_info/in ... 7x8mm.html

A silicone gasket, such as those from Cafelat, seem to be a lot more forgiving that the classic, harder gaskets. There have also been suggestions of shims under the gasket, though I don't know how successful that would be.

Specified at TSE.at as 72 x 57 x 8 mm Edit:
Durchmesser D1: ø 73,3mm
Durchmesser D2: ø 57,1mm
Höhe H: 8mm


http://www.cafelat.com/silicone-group-gaskets.html lists several gasket sizes. I didn't see one that was an exact match, unfortunately.

Grouphead gasket for Conti Prestina
Paolo wrote:I have a Cafelat 8.5mm (blue) gasket ...dimensions 73x57x8.5
http://www.cafelat.com/silicone-group-gaskets.html
with a 0.8mm spacer in mine.

I am using a LM portafilter.

The combination works well and gives a 6 o'clock handle when locked-in.
The above looks to be the "standard, E61" blue gasket, often available relatively inexpensively through regional espresso specialists and even some generalists.

Edit: based on @Kalo925's post (just below) noticing the dimensions on the TSE site, this looks like a poorer match that previously thought
Cafelat's "Astoria: 58mm 72mm x 56mm x 8mm" might seems like a stretch for it to work, but I'd check with Cafelat to see what they suggest.

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kalo925

#3: Post by kalo925 »

Jeff wrote: "Siebträgerdichtung Conti" is, I believe what we call a group gasket
https://www.tse.at/shop/product_info/in ... 7x8mm.html

Specified at TSE.at as 72 x 57 x 8 mm
If this is the size you have, you could try the Brugnetti Gasket @ 72 x 56 x 9. The link above says 73.3 x 57.1 x 8mm though.
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Paolo (original poster)

#4: Post by Paolo (original poster) »

Hi...thanks for your suggestions.
I have tried a Cafelat (blue) gasket and it is a dribbler with the Empress and in a Prestina it became a dribbler too. Three other vintage Contis that I have had experience with have all needed a Conti-sized seal of 73x57.7x9mm dimensions and 2x0.8mm shims underneath the seal (with an aftermarket grouphandle). The shims are there to get the locked-in grouphandle to come to the 6 o'clock position.


This Empress is different because (I think) the channel that accommodates the seal has no chrome plating...and it is just that little bit wider...so that a Conti seal doesn't work completely without dribbling either.



My guess is that this Empress would need a seal that is around 74x56x9.5mm...which is just not available anywhere that I have been able to find.

(I have found that a modern Conti lever just requires the 8.5mm thick seal....but a blue Cafelat seal is just a bit too small in OD and ID to seal without a dribble.)

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Jeff
Team HB

#5: Post by Jeff »

https://www.cafeparts.com/Products/Gask ... der-Gasket has filtering that can help find what might fit a set of dimensions. Though a US-based supplier, you may be able to source identified parts locally.

Guessing at ranges of 56-57 mm ID, 73-74 mm OD, and 9 mm or thicker, they show six options


Paolo (original poster)

#6: Post by Paolo (original poster) »

Gees thanks, Jeff!
#12747 looks pretty much just what I need.

Reneka is not a common brand in Australia but I have started to search.
The 74x56x9 gasket is certainly going to be worth searching for.

Thanks again,
Paolo

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Paul_Pratt

#7: Post by Paul_Pratt »

It is worth mentioning that the OD and ID of a seal is only there to hold it in place. The sealing side of things is done by the top and bottom sections. I would check that the surface of the group where the seal mates up to is free from scratches or gouges.

Is it normal for a Conti Empress to be chromed in that area? I have never come across any machine with anything plating in that area. You may get a "shadow" of nickel or something but they are generally left plain brass.
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Paolo (original poster)

#8: Post by Paolo (original poster) »

Hi Paul....thanks for chiming in here...

I removed the seal and shims and you were spot-on.

This old girl has been subjected to heavy hands in her past.


Is there something that I can do you remedy this?

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Paul_Pratt

#9: Post by Paul_Pratt »

Well I would suppose a smaller ID seal would help as it would seal on the ID as well.

If you cant find a smaller ID seal then you could use a paper spacer, but the spacer would have a little Loxeal 18-10 on the side against the damage. I mean in a pinch you could also use 18/10 without a paper spacer and put a little in the scratches.

If it were mine I would have the group off the machine, and machine the scratches away.

Paolo (original poster)

#10: Post by Paolo (original poster) »

Thanks for providing that tip.
I don't have access to an engineer that I would entrust with the Empress group, so I will give the Loxeal plan a try.

If you ever get any stainless springs made for the Empress, Paul....kindly give a shoutout. :)
I have had no success at all having a suitable spring made.