The guide to replace and install a 44.6mm conical burr set for a Breville coffee machines

1. Remove the Hopper and Outer Burr

• Empty the hopper and remove it by twisting it counter-clockwise to the “Unlock” or“Remove” position.
• Locate the outer burr (the ring with the handle). Turn it counter-clockwise to lift it out.
• Note: If the new burr set came with a silver shim washer, save it. Only add it later if the machine grinds too coarsely on the finest setting.

 2. Remove the Upper Burr Carrier

• Use a flathead screwdriver to pry out the metal or plastic washer holding the rubber seal (the “wiper”) in place.
• Remove the rubber seal to expose the three Phillips head screws beneath.
• Unscrew these three screws to lift the plastic carrier off the machine.

3. Remove the Lower Burr

• The lower burr is reverse-threaded. To loosen it, turn it clockwise.
• To lock the shaft, insert a Phillips screwdriver through the hole in the center of the gearbox (where the coffee usually falls out) to act as a stabilizer.
• Use a wrench on the hex nut of the lower burr to turn it clockwise until it comes loose.

 4. Clean and Install the New Lower Burr

• Clean out all old coffee grounds from the cavity.
• Screw the new lower burr onto the shaft. Because it is reverse-threaded, tighten it by turning counter-clockwise. Tighten firmly, but do not overtighten.

5. Install the New Upper Burr Carrier

• Place the new plastic carrier onto the machine.
• Reinsert the three Phillips screws.
• Replace the rubber seal and the metal retaining washer.

 6. Install the New Outer Burr

• Insert the new outer burr (the ring) into the carrier.
• Turn it clockwise to lock it in place.

 7. Reassemble and Calibrate

• Reattach the hopper and fill it with beans.
• Run a calibration: Set the grinder to the finest setting. If the motor stalls, sounds strained, or the burrs make a “metal-on-metal” screech, stop immediately and turn it coarser.

Pro Tip: If you find that even on the finest setting (e.g., "1" or "Fine"), the espresso runs too fast, you need to add the shim washer under the outer burr. If the burrs grind too fine and choke the machine, remove the shim if one was installed.

If your machine has aremovable magnetic upper burr (common in newer models like the Barista Touch Impress), the process is simpler—you typically just lift the handle, twist the outer burr out, and click the new one in without needing tools for the disassembly.