KRUPS piston on drainage valve

What is a brewing unit piston

The piston is a moving part of the brewing unit that presses the ground coffee under pressure into a compact puck and then forces hot water through it. Its precise movement and seal against the cylinder of the brewing chamber are essential for creating the pressure needed for coffee extraction.

When the part stops doing its job

• Weak or watery coffee lacking full flavor
• Water or coffee grounds leaking outside the brewing unit
• Unusual noise or grinding during unit movement
• Uneven coffee dosing or incomplete compression

Why you shouldn't put off the replacement

A worn or damaged piston loses its seal and precision of movement, which reduces extraction quality and can overload other parts of the brewing unit. Timely replacement prevents bigger failures and keeps the coffee taste consistent.

How to choose the right part

Pistons vary in size, shape, and mounting method depending on the specific type of brewing unit. Before purchasing, check compatibility in the product table to make sure the part fits your coffee machine.

Compatible with

• EA870810
• EA870840
• EA870880
• EA871A10
• EA877D10
• EA89W410
• EA910810
• EA910A10