ltetzner:
First, Welcome to our Forum.....
Will this help...?
With the handle in the Down position, it allows the Hydro Unit to power the tractor and hydro lifts.
With the handle in the Up position, the flapper on the under side of the cover, depresses the manual type Relief Valve buttons, thus creating a bypass relief pressure on the hydro unit. This will allow you to push/pull the tractor around.