Rocket flat gasket for the brew lever – the few-francs part that keeps the group sealed
Beneath the brew lever of the Rocket brew group sits a flat gasket. It seals the point where the valve mechanism exits the group body – where hot water is under pressure and yet something still has to be able to move.
Gaskets are the classic wear part: they harden, settle and take on an imprint. Then water leaks out, usually as a thin film that runs down the group body and shows up as a limescale trace. Because the part costs just a few francs and you open the group anyway to replace it, it belongs in every service.
When it is due
Water leaks out beneath the brew lever or a limescale trace appears. After brewing, a damp edge remains on the group. The removed gasket is hard, cracked or has a permanent imprint. Or the group is being serviced anyway – then a new one goes in, regardless of the condition of the old one.
At a glance
| Type |
Flat gasket |
| Location |
Brew group, at the brew lever |
| Fits |
Rocket espresso machines according to the manufacturer's information for number C219900426 |
| Scope of delivery |
1 gasket |
| Part number |
C219900426 |
| Installation |
Installation by a qualified technician recommended |
| Brand |
Rocket |
Important for installation
The gasket sits in the brew group, where water is under pressure and above 90 degrees Celsius. Before opening, the machine must be disconnected from the mains, depressurised and cooled down, and the replacement belongs in the hands of a qualified technician. We deliberately do not give step-by-step instructions here. What matters is that the sealing surface is clean and free of limescale before the gasket goes in – a new gasket on an old limescale edge will not last any longer than the old one.
Who it is for
For service workshops overhauling a Rocket brew group, and for anyone who has spotted a damp patch beneath the brew lever. Also as an inexpensive spare to keep in stock alongside the other group gaskets.
What goes with it
The same group also contains the brew group flange gasket, the group gasket 8 mm and the group gasket 8.5 mm. On the lever itself works the spring for the coffee brew lever, and for the group the brew group diffuser is the next part along the water path. For an overview, see Rocket accessories and spare parts; all original spare parts are listed under Original spare parts.
Workshop tip from Bern and Zurich: When we open a group because of one gasket, we replace all the gaskets in that group at the same time. The effort is the same, the parts together cost less than half an hour of labour – and we don't have to go back in three months. That is our experience, not a manufacturer specification. For the first shot afterwards we like to use Nutty Delight or Cozy Chocolate, or the stronger Very Nutty. More under Coffee beans.
No returns
Original spare parts are excluded from exchange and return. They are sourced to order and cannot be resold after installation or trial fitting on the machine. So before ordering, check the model, year of manufacture and serial number of your machine – or drop us a line and we will clarify the fit together. Your rights in the event of defective goods remain unaffected.
Frequently asked questions
What are the dimensions and material of the gasket?
The outer and inner diameter, thickness and material are not documented for us for this number. That is why we do not give any figures. Go by the part number C219900426, and it will fit.
How often should the gasket be replaced?
The manufacturer does not specify a fixed interval to us, and we won't make one up. In practice it is replaced when the group is open anyway or when that spot gets wet.
Is this the same gasket as the group gasket in the group head?
No. The group head gasket sits between the group and the portafilter and is a separate position. This one belongs to the brew lever.
Do I need grease or sealant?
Which aids are permitted on your machine depends on the material and is not documented for us for this number. That belongs in the hands of a qualified technician – we deliberately do not give a blanket recommendation.
Can I see the part in one of your showrooms?
Yes. We are in Bern at Gerberngasse 44 and in Zurich at Hagenholzstrasse 50b. Let us know shortly beforehand and the part will be ready for you.
Questions about the fit? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
