The rubber between pump and housing – and therefore between humming and quiet
A vibration pump beats against its own mass at mains frequency. So that this beating does not pass one-to-one into the sheet metal, the pump sits on rubber-metal buffers. This one measures 25 × 15 millimetres and has an M6 female thread on both sides, so it can be clamped between two screws.
As rubber ages, it becomes hard and cracked. The buffer then transmits instead of damping. You hear it as a new, throaty hum in the housing that gets louder during extraction – and you feel it on the worktop when you place your hand next to the machine.
When it is due
The machine hums noticeably louder during extraction than it used to, or transmits noticeable vibration to the worktop. The buffer is cracked, hard, shiny with oil or sunken. The thread has come loose from the rubber. Or the machine is being opened anyway and the old dampers have many years behind them – then it is worth replacing them at the same time.
At a glance
| Type |
Vibration damper, rubber-metal buffer |
| Installation location |
Inside the machine. The item description we have does not say on which assembly exactly. |
| Fits |
Rocket. Which series this number covers is not documented for us – please check before ordering. |
| Scope of delivery |
One damper. Screws and washers are not included. |
| Part number |
A849906258 |
| Version |
25 × 15 mm, M6 female thread on both sides |
| Brand |
Rocket |
| Installation |
Installation by a qualified technician recommended |
Who it is for
For anyone whose machine has suddenly become too loud, and for service businesses that renew the dampers as a matter of course during every major overhaul. A buffer that has gone hard costs little and changes a lot.
Important for installation
The damper sits inside the machine, close to mains voltage and water-carrying parts. Disconnect the machine from the mains, let it cool down and depressurise it before opening the housing. The buffer is tightened by hand, not with force – too tight, and the thread tears out of the rubber. We recommend installation by a qualified technician and deliberately give no step-by-step instructions here.
What goes with it
The category Rocket accessories and spare parts, our original spare parts and, as a comparable item from another brand, the La Marzocco anti-vibration rubber buffer M4 – different dimensions, same job.
From our workshop in Bern and Zurich
Our routine, not a manufacturer specification: when a machine has become louder overnight, we first place a flat hand on the lid and then on the worktop. If the worktop vibrates more than the sheet metal, the dampers are almost always worn out. It takes ten seconds and saves an hour of searching. And because you pull a shot after every job: we use Nutty Delight for this, because we know its curve by ear and by palate. Cozy Chocolate is the sweet cross-check, Very Nutty the candidate for milk. More in our coffee beans.
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 test fitting on the machine. So before ordering, check the model, year of manufacture and serial number of your machine – or drop us a quick message and we will clarify the fit together. Your rights in the case of defective goods remain unaffected.
Where exactly does this damper sit?
The item description does not tell us, and we do not guess here. What is stated are the dimensions 25 × 15 mm, the M6 female thread on both sides and the number A849906258. Send us the serial number of your machine and we will look into it.
How many do I need?
One damper is supplied. How many are fitted to your machine depends on the series – it makes sense to replace all of those on one component together so that the damping is even.
Are screws included?
No. The damper has an M6 female thread on both sides; the matching screws are not included in the scope of delivery.
Is this an electrical part?
No, it is purely mechanical. However, it sits inside the machine, which is why we recommend installation by a qualified technician.
Can I look at the part in your Showroom?
Yes. We are in Bern at Gerberngasse 44 and in Zurich at Hagenholzstrasse 50b. Bring the serial number of your machine with you and we will check the fit together at the counter.
Questions about the fit? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
