Service and Repair Manual June 2017Boom Components52 SX-180 Part No. 12684974-3Primary Boom Lift CylinderThe primary boom lift cylinder raises and lowersthe primary boom. The primary boom lift cylinder isequipped with a counterbalance valve to preventmovement in the event of a hydraulic line failure.How to Remove the Boom LiftCylinderBodily 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.1 Raise the boom until there is approximately4 feet / 1.2 m between the turntable and boomrest pad.2 Attach a lifting strap from an overhead craneor other suitable lifting device to the rod end ofthe the boom lift cylinder.3 Attach an overhead 10 ton / 9071 kg crane tothe platform end of the boom for support. Donot lift the boom.Note: Place the lifting strap between the cable trackassembly and the boom.4 Remove the boom storage area coverretaining fasteners. Remove the cover fromthe machine.5 Remove the pin retaining fastener from theboom lift cylinder rod-end pivot pin. Use a softmetal drift to remove the pin. Protect thecylinder rod from damage.Crushing hazard. The boom liftcylinder may fall when therod-end pivot pin is removed ifthe boom lift cylinder is notproperly supported by theoverhead crane.Crushing hazard. The boommay fall when the rod-end pivotpin is removed if the boom isnot properly supported by theoverhead crane.6 Place support blocks under the boom liftcylinder.7 Using the Auxiliary Power Unit, retract theboom lift cylinder until the rod end will clear theboom weldment.8 Carefully lower the rod end of the boom liftcylinder down onto the support blocks.
