Can't pull ink through Black ink line

What should I check if I cant pull ink through a line?

I started to experience issue with printing black, I replaced the black dampers and I cannot prime the dampers?

I did pull out a blue damper to see if my method was incorrect. But was able to properly syringe the blue thru.

Any suggestions what to check?

 

You maybe correct. I have all the covers removed and there are no kinks in the line. I can clearly see the black ink line from the cartridge is empty.

How exactly do you backflush the line?

 

It seem I was able to get the black to free up and now I can pull ink thru the installed dampers. To be sure I was making the right steps I also decided to change the blue dampers as well. When I stopped last night I was still not getting proper output from the cyan and the black. However the dampers (I changed) aren't completely full.

By running ink can I fill the damper from this point?
Or am I priming the dampers incorrectly

I'm trying to run solid cyan right now and I'm getting a yellow output? The cyan line looks blue...
Also The black I run has a magenta output.

 

RG I sincerely appreciate you devotion to my issue. The little charge did the trick, I cannot thank you enough. The cross contamination is gone and my test prints look PERFECT again!