The component that turns a lever movement into an extraction
When you raise the brew lever on the brew group, more happens mechanically than it feels like. The camshaft takes up the rotary movement and uses its cams to push the group valves open one after the other: first the path to the filter basket, then, as the lever returns, the pressure release. This sequence is why the portafilter is not under pressure after the shot.
The shaft runs inside the cast body of the group, is returned by springs and works at operating temperature. Cams and bearing points wear over the years – slowly and evenly, which is why you rarely notice the change and instead find one day that the lever no longer latches cleanly.
When it is due
The lever feels spongy, has more play than it used to or no longer latches securely at the top. This often comes with a change in sound: instead of a clear click, you hear a grinding noise or a double latch.
Another sign is after-dripping. If water keeps dripping from the group head after the lever has been returned, or if the pressure release fails and the portafilter stays under pressure, the shaft is no longer reaching its end position.
If you are taking the group apart anyway, take a look at the cams: if the contact surfaces are worn in, polished bright or angular instead of rounded, it makes sense to replace the shaft in the same job.
At a glance
| Type |
Camshaft for the brew group |
| Installation location |
inside the cast body of the brew group, behind the brew lever |
| Fits |
Rocket brew groups for which the manufacturer lists the number C219900425 or R229905238 |
| Scope of delivery |
one camshaft, without springs, cam kit and seals |
| Part number |
C219900425 / R229905238 |
| Design |
Metal, milled |
| Installation |
Installation by a specialist recommended |
| Brand |
Rocket |
Important for installation
To replace the part, the brew group has to be opened. Beforehand, the machine must be disconnected from the power supply, depressurised and cooled down – there is hot water in the group body. When reassembling, the position of the cams relative to one another is what matters: if the positioning is wrong, the group opens and closes in the wrong order. We deliberately do not provide step-by-step instructions here; this job belongs in experienced hands.
Who it is for
For service technicians and workshops overhauling a brew group and renewing the wear parts in one go.
For owners of older Rocket machines with a high shot volume, where after years the lever no longer switches cleanly. The manufacturer's documentation does not fully break down which model series are listed under this number – if in doubt, send us the serial number.
What goes with it
Often due in the same job are the cam kit with three pieces, the spring for the coffee brew lever and the flat gasket for the brew lever.
If the group as a whole no longer fits the bill, we carry it complete: Brew group Appartamento TCA and Brew group Boxer.
Further group parts can be found in Rocket accessories and spare parts, and you will find the section for the machine under Rocket Boxer spare parts.
From our workshop in Bern: before we take a group apart, we slowly move the lever through its full travel ten times and listen – with a flat hand on the cast body you can feel whether the shaft runs evenly or catches at one point. This is our own routine, not a manufacturer's specification, but it has saved us from replacing the wrong part more than once. Afterwards we pull a test shot with Cozy Chocolate, because its sweetness tells you straight away whether the extraction starts cleanly.
No returns
Original spare parts are excluded from exchange and return. They are sourced specifically for each order and cannot be resold after installation or a trial fitting on the machine. So before ordering, please check the model, year of manufacture and serial number of your machine – or drop us a short message and we will clarify the fit together. Your rights in the event of defective goods remain unaffected.
Frequently asked questions
Why are there two part numbers in the table?
The manufacturer lists this item under C219900425 and R229905238. Both numbers refer to the same part.
Are springs or cams included?
No. The shaft is supplied. The cam kit and the springs are separate items and are ordered separately.
Can I replace the shaft myself?
Replacing it requires opening the brew group and setting the position of the cams correctly. Without experience with E61-style groups, we recommend having it done by a specialist.
Does it fit my machine?
That depends on the type of group, not on the machine name. Send us the model and serial number and we will check it against the drawing.
Can I see the part in your showroom?
Yes. You will find us in Bern at Gerberngasse 44 and in Zurich at Hagenholzstrasse 50b. Bring the removed part with you, we will compare it with the replacement on site and you only take home what really fits.
Questions about the fit or the serial number of your machine? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
