Most of the hydraulic system failures are similar. That is there is a sudden or gradual loss of pressure or flow. Consequently, cylinders and motors in these systems may stop working. Any of the system components can be at fault. Possible causes of hydraulic cylinder faults and their rectification are highlighted below:

Possible causes	Rectification
General
Damaged/worn seals	-Replace seals
Excessive rod wear	-Prevent wear
Rod damaged	-Replace rod
Rod seized	-Repair
Faulty alignment	-Align properly
Broken linkages	-Replace damaged linkages
Loose mountings	-Tighten mounting bolts
Jerky movement	-Assemble piston packing correctly -Avoid heavy load  at slow speed
No thrust	-Replace faulty piston -Prevent excessive leakage -Set PRV to correct pressure
Abnormal cylinder thrust	-Bleed cylinder of entrained air -Check and set cylinder cushion
Erratic operation
Air in system	-Clean filters -Replace worn seals -Drain and flush fluid -Change system fluid -Fill reservoir to proper level -Tighten leaking connections -Bleed air from system -Replace worn shaft/seal
Cylinder/valve sticking/binding	-Remove dirt/gummy deposit -Remove fluid contamination -Remove worn parts -Install seals properly
Cylinder internal leakage	– Repair or replace worn parts –Tighten loose packing -Use medium viscosity fluid   -Control fluid contamination -Control wear

References:

Categories of malfunctions in hydraulic systems in terms of its general disturbances, and their possible causes and rectification are presented in the above books. Further, the component-wise malfunctions and their potential causes and rectification are also presented.

Joji Parambath

Director

Fluidsys Training Centre