A hydraulic system uses pressurized fluid to allow operators to lift heavy loads in an expected and repeatable manner. Often used in industrial and A&D applications, these systems must be reliable and durable to achieve operation success.

However, like any piece of equipment, hydraulic systems are at risk of malfunction or even total failure due to internal and external factors. Should risk factors be left unchecked, hydraulic malfunctions could result in injuries to personnel or anyone in the vicinity of the system, component damage, and expensive repairs.

While it is impossible to count for every possible factor that could negatively impact a system’s performance, understanding the common causes of hydraulic system failures can put you ahead of preventing an accident or malfunction.

1. Contamination

Reportedly the most common cause of hydraulic system failure is due to contamination. This can be caused by defective or fatigued pumps that introduce debris into the system. There are two common types of contamination to be mindful of – air and water.

• Air contamination: contamination created by air bubbles that leads to aeration or cavitation – often manifested by loud banging and knocking noise due to the implosion of air bubbles under pressure. This causes wear, damages components, and further contaminating the fluid with metal particles.
• Water contamination: contamination caused by water causes hydraulic fluids to have a milky appearance and can be caused by condensation build-up from temperature changes. Water in the system corrodes the pump, shortens component life, and can cause a multitude of other damages if allowed to freeze.

2. Improper Temperature Control

Improper temperature control can cause fluid viscosity problems which can result in hydraulic system component failure and a number of other problems over time.

• Too hot: In systems that cannot dissipate heat effectively, overheated temperatures can lower fluid viscosity, preventing proper lubrication, and increasing the risk of internal leakage, pump cavitation, and the thermal degradation of seals and other components.
• Too cold: Temperatures that are too low increase hydraulic fluid viscosity leading to higher stress on pumps, valves, fittings, seals, and other components. This often results in an overall shortened lifespan for the system and its components.

To learn more about temperature control for hydraulic systems, check out ThermOmegaTech’s Thermal Bypass Valves.

3. Human Error

It’s an unfortunate statistic that less than 5% of personnel tasked with maintaining hydraulic equipment receive less than adequate training, with the vast majority receiving no training at all. In addition, the engineers designing hydraulic systems often have a lack of system-relevant training and experience outside of a college required fluid dynamics course, which does not guarantee safely designed systems.

In fact, it is estimated that less than 1% of the hydraulic systems in operation today comply with the Occupational Health & Safety Administration’s (OSHA’s) Energy Control Procedure 1910.147 (c)(4)(i), which states: “Procedures shall be developed, documented and utilized for the control of potentially hazardous energy when employees are engaged in the activities covered in this section.”

Errors from this lack of knowledge and expertise result in improper installation, incompatible parts, and improper usage.

A recent Hydraulics & Pneumatics article boiled down the main concerns related to designing and maintaining hydraulic systems to 5 main contributing factors:

• Sub-standard engineering practices
• Sub-standard material specifications
• sub-standard building practices
• Code violations
• Poorly trained building workforce

To avoid human-error related accidents, it is important to conduct proper training for maintenance personnel, technicians, designers, and engineers, in the design, specification, and installation process of hydraulic systems.