I just had the dealer replace two of my waste gate valves under warranty. My problem was I broke the cable. I did use the twist on valve for several months until I could get it back to the dealer. It worked great at keeping the waste were it doesn't belong. Off my hands!!!
Before you decide to replace a valve, check to see if the cable is operating freely. You should be able to take down the basement wall to get a visual. My problem was about half of the 72" cable was tightly wrapped several times around the supply lines before it dropped into the underbelly down to the gate. This created a lot of tension that ultimately caused the cable to break.
If yours is wrapped the same you might be able to save it. Simply remove the handle and retaining nut and back feed it to untangle the cable to were it has one long curved sweeping arch down to the gate. Even if this doesn't work you'll at least have an idea as to how to install a new cable kit with valve.
You might also consider using a FLEX MEND - TRAP FLAP
to access the valve instead of dropping the underbelly.
There is a very good post by pirate about installing http://www.dutchmenowners.org/forums...lves-2682.html
that will walk you through the replacement process.