There is an upgrade kit for the purge and feed valves for the ink - to metal instead of the plastic ones. The ink eats at the plastic ones and they broke on us 1 or 2 times and are now upgraded so they shouldn't break again...
We didn't know about this upgrade when it was still under warranty unfortunately.
Just throwing this out there in case others didn't know. It could have to do with when you purchased your machine too, I would assume they upgraded them from the factory at some point.