# E61 seal size?



## Beemer (Jun 19, 2012)

I have read posts mentioning both 8mm and 8.5mm E61 seals. What might the reason be for the difference?


----------



## espressotechno (Apr 11, 2011)

8mm & 8.5mm are the depths (thickness) of the seals.

On a new machine the seal is 8mm.

After quite a lot of use (around 2 years) the group head grooves & the lugs on the portafilter wear - noticeable when the portafilter handle goes right round !

A new 8mm seal will then not be thick enough to bring the handle back to the 90 degree position. So an 8.5mm seal is fitted.

Sometimes an 8.5mm seal is *too* thick,in which case an 8mm seal + a shim (rubber or card) is fitted.

* Other commercial group heads - Gaggia, Cimbali, Rancilio,etc. - use the same replacement seal "system"

*A group seal lasts about a year, before the heat & pressure cooks it hard & leaky.

*It's best to fit a new shower cup /screen whenever a new group seal is fitted - can save a lot of hassle !


----------

