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Trouble Shooting of Hydraulic Cylinder Failure

Symptom	Possible Causes	Remedies
Piston rod scored	Contamination of the oil Contamination of the gland bearing Gland bearing failure	Flush entire hydraulic system Change all filters Check gland bearing
Cylinder bore scored	Contamination of the oil Piston bearing failure	Flush entire hydraulic system Change all filters Check piston head bearing
Bent piston rod	Operation problem possible overload. Outside impact. Under specification of piston rod	Check operation parameters. Increase rod specification
Split weld on base and ports	Shock loading. Poor original weld	Check operation parameters M/c off & re-weld correctly
Eye bearing broken	Shock loading Under specification of bearing. Overloading of cylinder	Check operation parameters Increase bearing specification Increase clevis pin size
Rod worn on one side	Lack of bearing support Too much side load Rod too small	Increase bearing area Change operation Increase rod size Incorporate external guides
Gland blown out	Possible intensification of internal pressure Threads worn Deformation of cylinder tube	Check hydraulic valve operation Check threads Check tube for oviality & thread wear
Leaking from around the gland od	O-ring failure Cracked gland	Check clearances Fit back-up ring to o-ring Crack test gland
Piston rod pitting	Corrosion	Upgrade rod material to marine specification Protect rod from weather
Barrel internally corroded	Water in the oil	Change oil Protect from water ingress
Regular seal leakage	Incorrect seals fitted Seal grooves corroded or marked Air trapped in the oilIncorrect metalwork clearances Contamination of the oil Seals fitted incorrectly Seal housing sizes incorrect	Check seal compatibility with conditions Check all seal grooves for marking & corrosion Make sure cylinder is bled correctly Check oil for contamination Check condition of all running surfaces
Cylinder is getting hot	Internal leakage	Test for internal pressure bypass Strip cylinder and inspect piston head & bore of tube Remove piston and check internal seal
Rod kick up at end of stroke	Internal bearing wear Incorrect alignment of piston to gland	Strip and inspect piston head & gland bearings Check alignment of piston to gland
Piston rod will not retract	Internal leakagePort blockage	Strip and inspect piston head & tube Check ports and pipes for blockages Check valve operation
Loss of power	Internal leakage Hydraulic pump failure Valve settings incorrect	Strip and inspect piston head & tube Check pump & valves
Slip stick or juddering	Lack of lubricant for the gland bearing & seals	Rough surface finishes on rod or tube Lack of hydraulic pressure Vacuuming or air entrapment Bearing tolerances too tight Seals too tight