I am getting ready to drain and refill coolant on my 2012 XKRS (x150). I have a manual and all steps are pretty clear except for one. There is a check valve right next to the expansion tank cap and the manual does not really really explain its operation.

1. When normally operating, should it be closed (like picture shows) or open?
2. When draining and refilling, should it be open (line aligned with the tube)?

Thanks,

 

Never mind, I made a mistake, it's not a valve, it's bleeding plug that needs to be removed when filling up and then tightened. Problem solved.