Thanks Walio. Case does a good job of hiding the release for that valve, and also keeping support info off the internet. Uncoupling the hoses worked like a champ.
I believe the knob you refer to is an over ride for the loader arm control valve, in case you lose the ability to raise the loader arms. That over ride will allow you to raise the loader arms to get them out of the way so that you can tilt the cab forward to work on things.