Can you hear the pump coming on when you start the printer?
There is a possibility that before replacing the dampers, there was already a "vacuum" for lack of better term that was holding the pressure of ink through line, through dampers and into capping station. But after replacing the dampers you lost that "vacuum" on ink through line, into damper and if the capping station is gummed up it won't allow for flow on inks as readily.
Compass Micro is the resource we recommend for replacement parts https://www.compassmicro.com/parts_search3.cfm
Start by replacing the suggested parts and while you're in there, double check the connection of your dampers and that they are seated snuggly onto the head, that the ink lines are securely screwed onto the dampers & not leaking.
Good Luck & keep me posted ,Kelly