Service and Repair Manual September 2016Hydraulic Pump70 GS-84 • GS-90 Part No. 12722226-2 Driv e Pum p6-2Drive 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 authorized servicecenter. Contact Genie Product Support to locateyour local authorized service center.How to R emove the Drive Pum pHow to Remove the Drive PumpComponent damage hazard. Thework area and surfaces wherethis procedure will be performedmust be clean and free of debristhat could get into the hydraulicsystem and cause severecomponent damage. Dealerservice is recommended.Note: When removing a hose assembly or fitting,the O-ring (if equipped) on the fitting and/or hoseend must be replaced. All connections must betorqued to specification during installation. Refer toSpecifications, Hydraulic Hose and Fitting TorqueSpecifications.1 Remove the lift/steer pump. Refer to RepairProcedure, How to Remove the Lift/SteerPump.2 Disconnect the electrical connections at theElectronic Displacement Controller (EDC)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 thepump coupler separates from the flex plate.6 Remove the drive pump from the machine.Component damage hazard. Thepump(s) may becomeunbalanced and fall if notproperly supported.Component damage hazard.When installing the pump, donot force the pump coupler intothe flexplate or damage to thepump shaft seal may occur.Component damage hazard. Besure to open the two hydraulictank valves and prime the pumpafter installing the pump.Note: Before installing the pump, verify properpump coupler spacing. Refer to Repair Procedure,How to Install Flex Plate.
