After 6 years, I have now cleaned once the turbine itself. A good guide how to do that I've found here: [...]
edit: Just looking at a known video portal to "How to clean a Dyson DC19 Vacuum turbine". Amazon does not allow direct links.
Then I looked at the filter. Here also a good video.
edit: "My Dyson DC19 has lost suction, how do I check the filter and change them to improve performance" Simple in a known video portal for Search. Amazon does not allow direct links.
However, I could not see through the yellow part of the pre-motor filter - so I decided to buy me new filter.
The delivered Hepa filter translucent to be good. It fits in any case without problems in my DC19.
The pre-motor filter, smell but after a week still strongly of plastic / rubber .. but he also fits easily into the Dyson.
I do not feel that the new filter has increased the suction power. So I had no problem. The Dyson sucks as ever.
These are not original Dyson accessories, this seems no longer to exist. Anyway, the prefilter was at Dyson no longer available on the website.