Troubleshooting - Valley Hydraulics

Issue

External oil leaks near seals	Visibly see external oil leakage around the components fitted with seals	Seals are damaged	Inspect seals for signs of damage
		Contamination in oil has damaged seals	Inspect seals for signs of damage and inspect fluid for evidence of debris
		Piston rod is damaged and has damaged seals	Fully extend the piston rod and inspect the surface for damage, also inspect seals for signs of damage
		Air trapped in the cylinder	Bleed the cylinder whilst looking for signs of air bubbles
		Over pressurisation	Check seal rating & check forpotential pressure intensification within the cylinder
		Seals not compatible with fluid media	Inspect seals for signs of damage and check the compatability of seal material with fluid
		Damage to the surface finish of the seal housing grooves due to corrosion	Inspect seal grooves for signs of corrosion
		Seal housing sizes incorrect	Dimensionally check and compare the seal groove sizes against manufacturers specification
		Incorrect seals fitted	Check seal part codes and ensure they match the manufacturers specification
		Metal to metal clearances around the seals are incorrect	Inspect all metal components for signs of wear then dimensionally check components against manufacturers specification
		Excessive side loading	Visually inspect metal components, bearing rings and seals for signs of excessive wear which will generally appear in one area

Piston rod damaged/bent	Visibly see external oil leakage where the rod enters the cylinder body, the movement during actuation may not be smooth and the pressure may need to be increased to actuate the cylinder	Debris in cylinder	Fully extend the piston rod and inspect the surface for scoring along the length and inspect the oil for signs of debris
		Excessive side loading	Fully extend the piston rod and inspect the surface for signs of excessive wear/damage in one area
		Structure or external part hitting the piston rod during operation	Fully extend the piston rod and inspect the surface for localised damage then observe the cylinder during actuation
		Cylinder loading greater than the piston rod rating	Check piston rod for signs of bending and check manufacturers operating parameters of cylinder against actual loadings
		Not enough overlap in the cylinder	Check piston rod for signs of bending and check for signs of wear on the surface of the rod where it has come into contact with other metallic components.
		Corrosion on the surface of the piston rod	Fully extend the piston rod and inspect the surface for signs of pitting, check the compatibility of rod material with environmental conditions

External oil leak near weld	Visibly see oil leakage around the weld	Shock loading	Visually check for oil leakage around the weld then check the operating parameters
		Defect in weld	Visually check for oil leakage and signs of cracking around the weld, there may be a slight pinhole causing the leak

Main tube bore scored	Cylinder may not hold pressure, the movement during actuation may not be smooth and the pressure may need to be increased to actuate the cylinder	Debris in cylinder	Inspect the tube bore, piston and piston seal for scoring along the length and signs of debris, also inspect the oil within the cylinder for debris
		Excessive side loading	Inspect the tube bore for signs of excessive wear in one area, also inspect the tube and piston for signs of metal to metal contact
		Clearance between metallic components	Inspect the tube bore for signs of excessive wear then dimensionally check components against manufacturers specification

Cylinder tube bore corroded	Cylinder may not hold pressure, the movement during actuation may not be smooth and the pressure may need to be increased to actuate the cylinder	Condensation due to temperature fluctuations in non-oil side of single acting cylinders	Inspect tube bore for signs of corrosion and check the tube material/coatings are suitable for the environmental conditions
		Water in the oil	Inspect the tube bore for signs of corrosion and inspect the oil in the hydraulic system for water

Main tube ballooning	Cylinder may actuate until it hits the ballooned area and then will not move or build pressure, a bulge may be apparent externally on the tube	Pressure intensification inside the cylinder	Check for signs of blockage on output ports, ensure no pressure spikes can occur during operation
		Cylinder tube rating is lower than the system pressure	Check manufacturers pressure rating for the hydraulic cylinder

Broken spherical bearing/bush	Visibly see damage to the bearing/bush	Overloaded	Check manufacturers operating parameters for the bearing against actual loadings
		Excessive side loading	Assess side loading and check figures/angles against manufacturers operating parameters for the bearing

Piston rod will not move	No movement of the piston rod when pressure is applied	Blockage in a port	Remove hoses and visually inspect the cylinder ports for signs of a blockage and check oil is present within the cylinder
		Valve failure	Replace the valve then check the piston rod moves
		Pilot line blocked in a pilot operated valve block	Replace the valve with a blanking plug and actuate the cylinder

Unable to build pressure in the cylinder

Cylinder may operate slowly, unable to build pressure in the cylinder or the cylinder will not hold its position when locked

Seal failure

Visually inspect cylinder externally in areas near to seals for signs of leakage and inspect all seals external and internal for signs of damage

Air in the hydraulic cylinder	Motion of the cylinder will not be smooth and it may appear to jump during actuation, cylinder may creep when locked off under load	System not fully bled during commissioning	Fully bleed the hydraulic system and re-test
		Not been bled following system components being replaced	Fully bleed the hydraulic system and re-test
		Faulty system components	Fully bleed the hydraulic system and re-test, ensure all system components are air tight and there are no faults with the equipment