Spare Parts for Rancilio Silvia Espresso Machines - V5 & V6. Shower Head Screw Holds the Shower screen in place. Not your regular thread screw so this one you want to take care of. Group Seal Over time the seal becomes hard and brittle, no longer making a good tight seal and letting water escape. You also know when it needs to be changed if your portafilters handles go beyond perpendicular to the machine when you lock them in. Basket Spring The achilles heel of the portafilter. Without on of these you'll be chasing your basket around wherever you knock out your coffee puck. Cheap part, but priceless.