The 7 Most Common Causes of Hydraulic Cylinder Failures

Hydraulic cylinders, which are key components of power hydraulic systems, are susceptible to a variety of failures despite their simple and robust design. Their reliability depends on numerous operational factors, the quality of components, and operating conditions. The most common causes of hydraulic cylinder failures are presented below, described using specialized industry terminology.

1. Wear and damage to seals

Piston and gland seals are responsible for maintaining the seal integrity and proper operating pressure in the cylinder. As a result of prolonged use, exposure to contaminants, or the use of unsuitable hydraulic oil, seals can wear out, crack, or delaminate. This results in fluid leaks, a drop in pressure, and reduced actuator performance.

2. Contamination of the working fluid

The presence of solid contaminants, such as metal shavings, dust, dirt, or water in hydraulic oil, leads to accelerated wear on the piston rod, piston, and seals. Contaminated hydraulic fluid can also cause control valves to stick, increase internal friction, and cause the system to overheat.

3. Incorrect operating pressure

Exceeding the operating pressure recommended by the manufacturer will overload the actuator, which may result in mechanical damage to the piston and piston rod, or even cause the cylinder to rupture. Conversely, insufficient pressure will reduce operating force and cause the system to malfunction.

4. Mechanical damage to actuator components

The most common types of mechanical damage include:

• bending or wear of the piston rod,
• scratches, pitting, and corrosion on work surfaces,
• cracks or deformation of the cylinder,
• damage to the guides and piston.

Such defects may result from mechanical impacts, operation in harsh environmental conditions, or improper installation.

5. Improper use and lack of maintenance

Failure to perform regular technical inspections, replace filters, and check the quality of the hydraulic fluid leads to accelerated wear of the actuator components. Prolonged operation without proper lubrication or with the wrong type of oil results in increased friction, overheating, and malfunctions.

6. Physicochemical reactions and material degradation

Contact between seals and working surfaces and an unsuitable working fluid, oil oxidation, and corrosion of steel components lead to material degradation. These phenomena are particularly dangerous in cases where water remains in the system for extended periods or where inappropriate additives are used.

7. Problems with control valves and manifolds

Malfunctioning of the valves that control the flow of the working fluid, as well as clogging or damage to these valves, can lead to unstable actuator operation, jerky piston rod movements, and uncontrolled position changes.

All of these factors lead to typical signs of failure, such as oil leaks, a loss of operating force, uneven cylinder operation, noise, or system overheating. Regular technical inspections, the use of high-quality hydraulic fluid, and adherence to the manufacturer’s operating recommendations are key to maintaining the high performance of hydraulic cylinders.