Before completing this preventative maintenance task, it is important to know what type of screen your machine uses. Machines using the E61 type group do not have a screw that holds the screen in place. The screen on this type of group is held in place by the gasket. Lever machines also do not use a screw. These are held in place by spring-type clips attached to the side of the screen.
- Remove the group screen.
- The group gasket fits inside a groove in the group head. It may be difficult to see the gasket, as heat will carbonize the rubber.
- If the group gasket has not been changed frequently it will become hard and brittle and will likely come out in chunks and pieces and may need to be “chiseled” or “picked” out. We recommend using a pick tool. Replacing with a silicone gasket solves this problem in the future.
- All of the gasket material must be removed and the groove cleaned thoroughly so that it is free of old-gasket debris and coffee residue. If not completely clean, the new gasket will not seat properly.
- Once the groove is completely clean, the new gasket may be installed. On machines that use the gasket to hold the group screen, make sure you replace the screen at this time otherwise, the screen can be replaced once the gasket is secured.
- Replace the group screen and screw at this time on machines that require it (this may be done afterward on Slayer and La Marzocco)
- Check the fit of the gasket and position of the portafilter. The portafilter should be in the 6 o’clock position, not too far to the left or the right. You can correct the gasket thickness by using paper shims if needed.
- Test for leaks. Done!