Folks! This might be a very noob question. But I'm a very noob pilot, so, whatever.Yesterday I was flying from LAX to SFO, and in cruise I had the FMS predicting a little more landing weight then expected. So I decided to finally test the fuel dump system.The fuel system was in Auto mode. The momment I click the Dump Fuel Switch, I get the Left and Right Dump Valve disagree alerts on my SD. So I took the QRH, and it says "verify all TRANSFER and XFEED valves are off". The thing is that they can't be turned off! The Systems Manual says the transfer and xfeed valves will be kept on if there is a problem on the dump valves. My question is: Am I really having a problem in the dump valves? I didn't click nothing in the "failures" menu, so I have no idea if that's a fault or I'm doeing something wrong...Can I dump fuel at all in that situation?Any feedback would be appreciated,Thaks!

Fuel dumping in the MD11 is not the on/off thing it is with other aircraft, instead, use you use FMS (init page 3) to set the "Dump to Weight" to indicate the gross weight you want to dump to. This would usually be your max safe landing weight. Then any time during the flight you need to divert to alternate and need to dump you can just hit the switch. The system will dump until the specified weight is reached and turn itself off. This has the advantage that you are not trying to do landing calculations while dealing with the situation that made you divert in the first place.If you are already below the Dump To weight, then the valve disagree message is telling you that the valves are closed (because dumping has been stopped) but the switch is still open.

It is normal to get that while the valves are moving. Once in position, all should be working as expected.