Change espresso machine group seals

Leaking coffee over your group handles?

The life of a group head gasket is not a happy one. All day it sits in a 90 degrees celcius group head, while the group handle also at 90 degrees celcius is locked in against it (often with a good dose of ground coffee), released and then re-locked in. This all means that your group gasket has a pretty short life expectancy, which is shortened even more the greater the number of drinks you make. When the gasket dies, you will notice coffee leaking down the group handle when you brew coffee, and definately when you backflush the machine (you do backflush, don't you?)

Below are some quick tips for replacing the group gasket on common machines:- Wega - or any other machine with a Faema E61 group. The E61 group is a massive chunk of brass (See Right), when assembled and ready to place on a machine it weighs in at 9 lbs. This weight mass contributes to its ability to maintain a consistent temperature. The other function that helps with this temp stability is the thermo syphon function; this is a function of water circulation that reduces hot spots within the group head. A very simple system that is worth its weight in crema.

The other type of diffuser and gasket combo are pictured right, you will know if your group is of this type by looking up and seeing if their is a flathead screw in the centre. If so unscrew the screw and lever the diffuser down and it will drop out. On some groups (particularly Gaggia machines) you will have to remove the breaker plate - this has two Allen Key screws which you will need to undo and remove the big chunk of metal known as a breaker plate. Soak this in cleaning powder and hot water to remove built up oils. If you can see allen key screws in the group their is no way you can get the gasket out without taking the breaker plate out. If their are no screws or you have taken out the breaker then screw a long wood screw into the gasket until it is tight, and then use mole grips to grab the screw and pull it down, which should pull out the gasket. It might take a few goes, and the longer the gasket has been in the group it will be brittle and hard like pot. Once the gasket is out, use a metal bristle brush to scrub the metal plate clean of coffee oils, and make sure the gap where the gasket goes is clean. Push in the new gasket, then re-fit the breaker if present and then screw in the new diffuser plate.

The guides below are from www.wholelattelove.com

Rancilio

1. Unplug the machine
2. Remove the reservoir, drip tray and drip pan and lay it on its back.
3. Use a short wide blade screwdriver to remove the shower screen. Under the shower screen is a “water jet breaker” that will come out with the shower screen be careful not to lose it. If you use a small bladed screwdriver it might strip the screw.
4. Find a couple of screws that you might have lying around. They do not have to be any special size. Screw them into the old gasket. I have found that a sheet metal screw with a 5/16”or 1/4” six sided head and a ratchet works perfectly. Make sure that they are across from each other. Do not go completely through the gasket just screw them in far enough to get a good grip. You can judge this by looking at the new gasket you are going to install. The gasket depth is about 5/16”.
5. Use pliers to pull on the screws and work the old gasket out. Pull one side and then the other until it comes out.
6. This is a good opportunity to clean the shower screen and brew group. The cleaner they are the better the coffee. It does make a difference.
7. Clean and dry the slot in the machine that the gasket fits into.
8. Slide a new gasket into place. Make sure the inside edge that is beveled is facing up.
9. Install water jet breaker and shower screen.
10. Tip the unit back up and install the drip pan, drip tray and water reservoir.
11. Fill the reservoir and plug the machine in and you are ready to go.

Gaggia

1. Unplug the machine
2. Remove the reservoir, drip tray, drip pan and reservoir cover and lay it on its back.
3. Use a short Philips head screwdriver to remove the shower screen.
4. Under the shower screen you will see the “Shower Holding Plate” that is help in place with two Allen screws. Remove the two Allen screws with 5mm Allen wrench.
5. Use a large flat blade screwdriver to gently pry out the “Shower Holding Plate”. Be careful not to damage the ridge that the shower screen fits up into.
6. Find a couple of screws that you might have lying around. They do not have to be any special size. Screw them into the old gasket. I have found that a sheet metal screw with a 5/16”or 1/4” six sided head and a ratchet works perfectly. Make sure that they are across from each other. Do not go completely through the gasket just screw them in far enough to get a good grip. You can judge this by looking at the new gasket you are going to install. The gasket depth is about 5/16”.
7. Use pliers to pull on the screws and work the old gasket out. Pull one side and then the other until it comes out.
8. This is a good opportunity to clean the shower screen and brew group. The cleaner they are the better the coffee. It does make a difference.
9. Clean and dry the slot in the machine that the gasket fits into.
10. Slide a new gasket into place.
11. Put the machine back together.
12. Tip the unit back up and install the drip pan, drip tray and water reservoir.
13. Fill the reservoir and plug the machine in and you are ready to go.