A tool bar and hydraulic system for a large scale agricultural implement. The tool bar includes opposed pivotable wings that are extended in a field configuration and retracted in a transport configuration. In some embodiments, each pivotable wing includes two lift assist assemblies for aiding in the execution of turns in the field, and for aiding in the transport of the agricultural implement. The tool bar may be configured to compensate for twist of the pivotable wings when in the transport configuration. The hydraulic system provides a “stiffening” of the tool bar for lift assist during field operation while providing for flexing of the tool bar during transport.