Digital BW, The Print

i have a mis continious flow system with org b w colour
and a 1200 epson printer

i first thought that my tubes are blocked 
but now i cleaned them and the problem still was there
so i tried to pull out some ink with a syringe without the tubes atached

on 2 colours i still feel a lot of resistance when i pull back the
syringe   so the problem must be inside the cartridge 

any ideas how i could clean a cartridge 

sure a new one would be the easiest but i am not from usa and i dont
have a credit card so it is very difficult to order stuff from usa

thanks for any help 

freduardo