Service and Repair Manual September 2016Boom Components48 Part No. 12685565 Place blocks under the primary boom liftcylinder linkage arms for support.6 Tag, disconnect and plug the primary boom liftcylinder hydraulic hoses. Cap the fittings onthe cylinder.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.7 Remove the pin retaining fastener from theprimary boom lift cylinder rod-end pivot pin.8 Use a soft metal drift to remove the pin.Crushing hazard. The primaryboom will fall if not properlysupported when the pivot pin isremoved.Crushing hazard. The lift cylinderwill fall if not properly supportedwhen the pivot pin is removed.Crushing hazard. The primaryboom lift cylinder linkage armsmay fall if not properly supportedwhen the pivot pin is removed.9 Remove the primary boom lift cylinderbarrel-end pivot pin retaining fasteners.10 Use a soft metal drift to remove the barrel-endpivot pin. Remove the primary boom liftcylinder from the machine.Crushing hazard. The lift cylinderwill become unbalanced and fallif not properly supported whenthe pin is removed.4-4Primary Boom Extension CylinderThe primary boom extension cylinder extends andretracts the primary boom extension tube.Theprimary boom extension cylinder is equipped withcounterbalance valves to prevent movement in theevent of a hydraulic line failure.How to Remove the PrimaryBoom Extension CylinderBodily injury hazard. Thisprocedure requires specific repairskills, lifting equipment and asuitable workshop. Attemptingthis procedure without these skillsand tools could result in death orserious injury and significantcomponent damage. Dealerservice is strongly 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.Note: Perform this procedure with the machine on afirm, level surface and in the stowed position withthe axles extended.1 Raise the primary boom to a horizontalposition.2 Extend the primary boom until the primaryboom extension cylinder rod-end pivot pin isaccessible.
