Need Help Best procedures for finding slight air leak?

[dreko]

I've got a LEC2-300 that keeps dropping yellow ink. I've replaced the damper and capping station with OEM, yet it's still happening.
Once I do a power cleaning to pull all air thru.. it's perfect.. until the next print.. then the yellow starts to fade

The choke valves located behind the ink cartridges apparently do fail in time. Should I just put a syringe on the inkline just above the inlet on the damper then pull?
If ink is pulled while choke valve is closed, that would indicate a failed/failing choke valve yes?

Never replaced a choke valve, but it looks super easy, no? Tricks or thoughts?

appreciate any advice, suggestions or tips
thank you

 

[cornholio]

I'd insert a cleaning cartridge and flush the line. Then close the choke valve and suck at the damper or the damper connector. Then look for bubbles. Replacing the valve should be straight forward.

 

[dreko]

Ok thanks, I'll find out about ordering a cleaning cartridge.. I"m guessing I'll need 8 of them, no? Rolands don't allow a single channel/color flush.
So if I'm doing a ink renewal or ink empty.. it's going to do this to all 8 slots, yes?

How many mil of ink should I pull through the damper to get air out of line/damper? 5mil , 10mil?

thanks for the help