I noticed on the last rebuild that the filter was looking decidedly black, so i ordered a 'recharge' kit and gave it a good ole scrub!
This is how it started;
![Image](http://www.bxproject.co.uk/gallery2/d/4760-5/KnN+3.jpg)
Black, furry and otherwise grim. Its a mixture of solidified diesel fumes, soot, grit, dead insects and bits of tree. All in all not good for breathing, and probably not to wonderful for the emissions. The kit was bought from the eVil bay for about £10.
![Image](http://www.bxproject.co.uk/gallery2/d/4768-5/KnN+6.jpg)
I set about cleaning it, initially following the instructions, but not for long. The instructions say spray the cleaner on, give it exactly 10 minutes and gently rinse it off, repeat if required. Well what a load of rubbish. After the third 'soak' i dialled the pressure up on the rinsing water (opened the tap a bit more) and ramped up the flow temperature (opened the hot tap), i also grabbed an old paint brush to get right into the crevices. 20 minutes later i had something that actually looked half way to clean. I applied the oil (included in the kit) and left it to dry.
The final cleaned filter looked like this;
![Image](http://www.bxproject.co.uk/gallery2/d/4776-5/KnN+8.jpg)
It's not perfect, there are still blackened patches, but it's much much cleaner. I don't have any easy way to measure the airflow through the panel, but i would imagine it is an improvement. It might be possible to get it that bit cleaner, but i was concerned about damaging the filter and not knowing it until too late!
Simplz!