Hudson Reed basin tap

[paul243]

I have a cold water basin tap(quarter turn) which is leaking slightly from the top,under the handle. There is no drip or leak from the central spout outlet when off so I presume the ceramic cartridge is ok.
It only leaks when the tap is turned on,fine when off.
I have replaced the "barrel" (has two black bands) and handle with new but still leaks.
If I replace the ceramic cartridge will that cure it or could it be wear in the tap where the barrel locates? I presume I have to remove the tap to replace the cartridge,are they available as a part?
Hope this makes sense
Thanks

 

[paul243]

Can anyone explain please how to remove the ceramic cartridge, does the body of the tap unscrew or do I have to remove the tap and dismantle?
It's a HR Tec 3 hole mixer.
Thanks