February 2017 Service ManualFuel and Hydraulic TanksPart No. 1259369GT S-80 • S-85 • S-80X 1339-2Hydraulic TankThe primary functions of the hydraulic tank are tocool, clean and de-aerate the hydraulic fluid duringoperation. The tank utilizes internal suctionstrainers for the pump supply hoses and has anexternal return filter equipped with a filter conditionindicator.How to Remove the HydraulicTankComponent 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 fuel tank. Refer to RepairProcedure, How to Remove the Fuel Tank.2 Close the two hydraulic tank valves located atthe hydraulic tank (if equipped).Component 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.open closed3 Remove the drain plug from the hydraulic tankand completely drain the tank into a containerof suitable capacity. Refer to Specifications,Machine Specifications.4 Tag, disconnect and plug the two suctionhoses that are attached to the hydraulic tank.5 Tag and disconnect and plug the hose fromthe return filter. Cap the fitting on the returnfilter housing.6 Tag and disconnect and plug the supply hosefor the auxiliary power unit. Cap the fitting onthe hydraulic tank.
