REV CSection 4 • Repair Procedures4 - 64 GS-3384 Part No. 82259September 2005HYDRAULIC PUMPS6-2Drive PumpThe drive pump is a bi-directional variabledisplacement piston pump. The pump output iscontrolled by the electronic displacement controller(EDC), located on the pump. The only adjustmentthat can be made to the pump is the neutral or nulladjustment. Any internal service to the pumpshould only be performed at an authorizedSundstrand-Sauer service center. Contact theGenie Industries Service Department to locateyour local authorized service center.How to Remove the Drive PumpComponent damage hazard. Thework area and surfaces where thisprocedure will be performed mustbe clean and free of debris thatcould get into the hydraulic systemand cause severe componentdamage. Dealer service isrecommended.When removing a hose assemblyor fitting, the O-ring on the fittingand/or hose end must be replacedand then torqued to specificationduring installation.Refer to Section Two, HydraulicHose and Fitting TorqueSpecifications.1 Remove the lift/steer pump. See 6-1, How toRemove the Lift/Steer Pump.2 Disconnect the electrical connections at theEDC located on the drive pump.3 Tag, disconnect and plug the hydraulic hosesfrom the drive pump. Cap the fittings on thepump.Bodily injury hazard. Sprayinghydraulic oil can penetrate andburn skin. Loosen hydraulicconnections very slowly to allowthe oil pressure to dissipategradually. Do not allow oil tosquirt or spray.4 Support the drive pump with a suitable liftingdevice and remove the two drive pumpmounting fasteners.5 Carefully pull the drive pump out until the pumpcoupler separates from the flex plate.6 Remove the drive pump from the machine.Component damage hazard.Be sure to open the two hydraulictank valves and prime the pumpafter installing the pump.Before installing the pump, verifyproper pump coupler spacing. See4-3, Flex Plate.Models with hydraulic tank shut-off valves:Component damage hazard. Besure to open the two hydraulictank valves and prime the pumpafter installing the pump.Models without hydraulic tank shut-off valves:Component damage hazard. Besure to fill the hydraulic tank tospecification and prime the pumpafter installing the pump.
