Brass bushing for the KB90 locking mechanism – so the portafilter clicks in audibly again
The KB90 has its special feature right in the way it is operated: the portafilter is inserted straight and locked, without a twisting movement. This very locking mechanism is the part that works hardest in a café – hundreds of times a day, with momentum and under pressure. The brass bushing inside is the sacrificial part that absorbs the wear.
This bushing is made of brass and has a bore of 8 millimetres, an outer diameter of 8 millimetres at the guide and a height of 4,2 millimetres. The manufacturer lists it for the locking mechanism of the KB90 under part number F.8.016. One bushing is supplied.
When it is due
The portafilter no longer clicks in clearly or comes loose too easily. The locking mechanism has play or feels stepped. It rattles when inserting. Or the removed bushing shows an oval bore and worn end faces.
At a glance
| Type |
Brass bushing for the locking mechanism |
| Installation point |
Locking mechanism of the brew group |
| Fits |
La Marzocco KB90. For conversions to version 2.0: send us the serial number and we will check the fit. |
| Scope of delivery |
one brass bushing |
| Part number |
F.8.016 |
| Version |
Brass, 8 x 8 x 4,2 mm |
| Installation |
Installation by a specialist recommended |
| Brand |
La Marzocco |
Important for installation
The bushing is part of the locking mechanism on the pressurised brew group. We do not publish step-by-step instructions for it: the machine must be disconnected from the power, depressurised and cooled down, and after installation it must be checked that the locking mechanism holds securely. A lock that opens under pressure is not a cosmetic problem. This is a job for a specialist – or for our workshop.
Who it is for
For cafés with a KB90 in constant use whose locking mechanism has developed play over the years. For service technicians who overhaul the locking mechanism and renew bushing and screw together. And for businesses that keep such small parts in their spare parts case.
What goes with it
All parts for this series are available in Spare parts for La Marzocco KB90, the brand at a glance in Accessories and spare parts for La Marzocco, everything from our service stock in Service parts. To go with it, add machine and grinder cleaning, because coffee oils in the guide accelerate wear.
Workshop tip from Bern and Zurich
Our own routine, not a manufacturer's specification: on the KB90 we check the locking mechanism with the empty portafilter in semi-darkness – you can hear immediately whether the click is solid or dull. And we always change the bushing and the matching screw together, because a new bushing on a worn screw becomes oval again. Then we pull a test shot, preferably with Nutty Delight. Sweeter with Cozy Chocolate, stronger with Very Nutty. Everything else in our coffee beans.
Returns excluded
Spare parts are excluded from exchange and return. They are procured to order and cannot be resold after being installed or test-fitted 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
Is the matching screw included?
No, the bushing is supplied on its own. The screw for the KB90 locking mechanism is a separate position – we recommend replacing both together and are happy to put this together for you.
Does the bushing fit every KB90?
It is listed under F.8.016 for the locking mechanism of the KB90. Because the locking mechanism is also available as a version 2.0 kit, send us the serial number and we will check it in advance.
Why brass and not steel?
Brass slides well and absorbs the wear instead of passing it on to the surrounding parts. That is why the bushing is a scheduled wear part.
Can I replace it myself?
We recommend a specialist. It is a locking mechanism on a pressurised group, and it must hold securely after installation.
Can I look at the part in your showroom?
Yes. We are in Bern at Gerberngasse 44 and in Zurich at Hagenholzstrasse 50b. Let us know shortly beforehand and we will have the part ready.
Questions about the fit? Write to us with the model and serial number at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
