246Service Manual – Advance 7765 / Nilfisk CR1500Wheel System, TractionFunctional DescriptionOverviewThe traction wheel system includes the hydraulic drive wheel motor and drive pump, and the foot pedal andassociated components that control the direction and speed of the drive wheel motor.The drive wheel motor is driven by the variable-displacement drive pump which allows speed and directionalcontrol. The drive pump and drive wheel motor hydraulic system is a closed system, but allows forprogrammed oil leakage through the drive pump for lubrication and cooling purposes. This leaked oil returnsto the reservoir and requires make-up oil that is supplied to the drive pump through the charge circuit.Drive PumpThe Drive Pump is driven by the engine and powers the hydraulic drive wheel motor. Note that the DrivePump was changed in early 2010, beginning with machine serial number 1000034942, from part number7-60-05026 to part number 56514943. This change also included changes to the forward/reverse controls.Drive Pump Before Machine Serial Number 1000034942The Drive Pumpon machinesbefore serialnumber1000034942 ispart number7-60-05026.To ReturnBlock/ManifoldTo ReturnBlock/ManifoldTo FrontPort on RearWheel MotorTo Rear Port onRear Wheel MotorFrom SqueegeeVacuum FanMotor Drive Pumpp/n 7-60-05026
