vitomatt wrote:Seems very odd to me that the hole is... irregularly shaped

As shown in the diagram above, the hole is drilled at a sharp angle into solid brass, so it can't be perfectly round.

Yeah, and there's no way that any corrosion from normal tap water could eat through inch thick brass, not without killing something else in the machine before it ever got that serious. But, if you were running Hydrofluoric acid...

seeing is believing!
H-B strikes again with an answer!
Jon, thanks for posting the other pics.
Now get that gasket shim and let's party on!

Oh - anyone know if other machines also have a similarly type drilled hole for water dispersion?

My $.02 ... It looks pretty filthy in there. There is sufficient evidence that a wire brush was used, but there is a lot of coffee debris. I wonder if it looked like that in the gasket's recess? You can see a good amount of coffee between the gasket and the group. That could cause problems. Remove the gasket and water reservoir, and turn the machine upside down. Use a solution of backflush detergent and soak and clean the brewgroup. You might put a small cloth in there and saturate it with the solution. Get all that coffee and of gasket out of there before installing the new one.

vitomatt wrote:Oh - anyone know if other machines also have a similarly type drilled hole for water dispersion?

E61 also has a pair of (~45°) tubes from the gicleur chamber to the grouphead, as shown in the classic diagram developed by Lino Verna:


From E61 Group Espresso Machine: Detailed Interior Schematics.

Randy G. wrote:My $.02 ... It looks pretty filthy in there. There is sufficient evidence that a wire brush was used, but there is a lot of coffee debris. I wonder if it looked like that in the gasket's recess? You can see a good amount of coffee between the gasket and the group. That could cause problems. Remove the gasket and water reservoir, and turn the machine upside down. Use a solution of backflush detergent and soak and clean the brewgroup. You might put a small cloth in there and saturate it with the solution. Get all that coffee and of gasket out of there before installing the new one.

Good call, Randy. Like I said, it wasn't in my cleaning practice to remove the shower screen. Guess I should get into that.

Before I install the new gasket, I'll do what you said above.

cheers!

godlyone wrote:Excuse the crappy pic, but my grouphead looks a little bit different than yours.

The showerhead has a metal piece before it which goes into an indent. The "hole" you speak of is in that indent, and shoots into the metal piece (metal piece is a diffuser)

Also my "hole" is not as rough as the one in your picture. Is your silvia an older model? I didn't know they changed the grouphead?

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My Silvia is only 2 years old. It's not the latest model with the new spiffy portafilter handle and steam valve, but the model before that. I purchased my machine new in the fall of 2007.

Interesting that your Silvia has a hole in a different place. When was yours produced?

I don't have my (old) Silvia any more, but I'm pretty sure I remember it looking like godlyone's (i.e. the older version); it only has the jet breaker + shower screen that attach to that central screw. I assume that Tag Team Jesus's is the newer (pod capable) model with a big hunk of brass that directs water flow + can be swapped for the pod adapter.