I heard back from Rod, here's what he said:
Epson does not sell the dampers separately for this machine. It is much like the Stylus Pro 3800/3880 in that the entire ink supply unit is a single part. In this case, the ink supply unit is reference number 501 in the parts diagrams. Below is the Epson part number, description, and our reseller price:
1539519 ink supply unit $137.91 each - special order (Epson list price is $172.39)
Epson shows this special order item in stock.
We would be able to ship this item out from Vancouver, WA 3-4 business days after the order is placed. Shipping to you is in addition.
If we are shipping to a location within the state of Washington, then sales tax would be in addition.
Please be aware, we do not accept returns of any kind on special order parts, and instructions are not included.
Please give us a call at 800-388-8595 to place an order.
We are open 8AM - 5:30PM Pacific time Monday - Thursday, and 8AM - 4:30PM on Fridays.
I can tell you from my own experience (though I am not a certified Epson tech, or engineer- but have years of experience working on many different Epson printer models), as the R3000 has a lot of similarities to the 3800/3880 (which Epson also only sells the whole ink system for, and not just the damper assembly). I replaced individual dampers in the damper assembly of our 3800, and it's been working great ever since. Other customers have done the same with their 3800/3880 printers, and even posted helpful info and photos of their experience. I can not direct or recommend people to work on their printers differently than the Epson repair manual specifies, but can share my experience, and direct you to threads where others have shared helpful info (which is the awesome thing about the forum community). Here are two helpful threads with info and photos: http://www.inkjetmall.com/tech/showthread.php?512-Epson-3800-ink-selector-assembly-disassemble- and http://www.inkjetmall.com/tech/showthread.php?228-3800-LC-channel-completely-missing/page2
I hope this helps. Please keep me posted, let me know if you ave questions, or there's anything else I can help you with.
Best regards~ Dana