Conti Empress group seals not wide enough - Page 2

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#11: Post by kalo925 »

Paul_Pratt wrote: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.
I'm in the process of getting a Aurora Brugnetti back in shape and didn't really think about this before until I read what you wrote. In fact there are grooves on both the inside and outside diameters in the group walls where the seal is inserted on the Brugnetti. On the inside one there are two different circumferences, above and below the very small groove, with the lower one being stepped slightly larger. Do you know the reasons for these small grooves? I'm a bit perplexed too as everything for the AB says it should be 72x56x9mm, but the one I pulled out is 74x58x8.5mm and actual measurements inside are ~74x58mm. Perhaps the one available now is for machines that are relatively new (maybe not the old levers?). I don't feel like stretching the new one 2 mm is reasonable. Do you?

Edit: I just pushed the seal in there and actually seems ok. Maybe it's intended to be stretched some...? Hard to really know and understand some of these things without some written explanation of the engineering behind all of these different design approaches. Also in the photo I took, the gasket is upside down, will be inserted the other way. I guess the raised Aurora and number do not effect that lower sealing surface... ? :)

Paolo (original poster)

#12: Post by Paolo (original poster) »

As a follow-up-
I sourced a Reneka group seal (74x56x9mm), which has a 1mm wider O.D and a 1.7mm wider I.D.than an OE Conti seal (73x57.7x9mm).

I used some Loxeal and a 0.5mm shim.... and with the Reneka seal fitted and after around 6 shots can report that (so far) the surgery was a complete success!

The portafilter handle locks in at 5 o'clock and there are no dribbles. All of the pressure generated by the spring on the coffee bed has led to much better extractions as well.

A big shout-out to both Jeff and Paul for your assistance. I had an Empress coffee for each of you!