Lower Group Head Mushroom O-ring

Lower Group Head Mushroom O-Ring, EPDM 04075

This EPDM o-ring seals the lower mushroom valve inside the group head, the disc that opens to let hot water reach the puck on every shot. It's a wear item, EPDM handles the heat cycling well, but the ring still hardens and loses its seal over years of daily brewing.

SPECIFICATIONS

• O-ring 04075, EPDM, 3.53 mm thick, 18.64 mm ID

COMPATIBILITY

• Fits: Group heads using the lower mushroom valve with a 04075-size o-ring

INSTALLATION

Technician-level job, the group head has to be partially disassembled to access the lower mushroom, so this isn't a five-minute counter repair.

PRO TIPS

• A failing lower mushroom o-ring shows up as water dripping from the group between shots, not during brewing, if you're chasing a group head drip and the gasket and screen are fine, this o-ring is the next suspect.