Clogging while printting yellow

[lerscom]

Hi, I have the epson gs6000, recently i been having this problems, while printing, the yellow ink gets clogged, and when I use the clean cycles it clogs the blue and I have to do several clean cycles to get all the head right, I call the tech. and they have change the caps twice but the problem still there, does anyone knows what could be causing this?
Thanks for any info.

 

[Robert M]

Gs 6000

What brand ink are you using?

 

[lerscom]

I´m using original ink, I shake it constantly to maximise the ink usage