Case Drain Line Pressure Switch With Automatic Fan Drive Motor Shutdown

A case drain circuit particularly well suited for use with a bulk fill subassembly or a vacuum fan assembly of an agricultural implement towed by a tractor or similar vehicle includes a pressure switch that may cause illumination of an in-cab warning light and/or sounding of an in-cab alarm when pressure in the case drain circuit exceeds a predetermined threshold. A fan is driven by a solenoid controlled hydraulic motor which is supplied hydraulic fluid under pressure from a flow control valve to the motor in accordance with electrical signals that are supplied to the solenoid by a controller. The case drain circuit provides a pathway along which leakage fluid from the motor may be delivered to a fluid reservoir, preferably carried by the towing vehicle. During undesirable high pressure conditions in the case drain circuit, the pressure switch provides a corresponding high pressure signal to the controller that in turn cuts electrical current to the solenoid to cut the flow of hydraulic fluid to the motor.