Service and Repair Manual April 2018Hydraulic Pumps94 ZX®-135/70 Part No. 1279835GT7-2Drive 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 be performed at an authorizedSauer-Danfoss service center. Contact GenieProduct Support to locate your local authorizedservice center.How 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 Disconnect the wiring plug at the electronicdisplacement controller (EDC), located on thedrive pump.2 Locate the two hydraulic tank valves at thehydraulic tank. Close the valves.open closedComponent damage hazard.The engine must not be startedwith the hydraulic tank shut-offvalves in the closed position orcomponent damage will occur. Ifthe tank valves are closed,remove the key from the keyswitch and tag the machine toinform personnel of thecondition.3 Tag, disconnect and plug the hydraulic hosesfrom the drive and function pumps. Cap thefittings on the pumps.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 pumps with a suitable liftingdevice and remove the two drive pumpmounting fasteners.
