Identifying Symptoms and Preventing Common Hydraulic System Failures

Presented by Amindus Consulting and Solutions

Hydraulic systems power many machines and vehicles, from construction equipment to manufacturing tools. When these systems fail, downtime and costly repairs often follow. Knowing the common types of hydraulic system failures, their symptoms, how to diagnose them, and ways to prevent them can save time and money. This post covers four frequent hydraulic system problems: internal leaks, overheating, cavitation, and pressure loss. Each section explains what to watch for, how to identify the root cause, and practical tips to keep your system running smoothly.

Internal Leaks in Hydraulic Systems

Symptoms to Look For

• Reduced system efficiency or slower actuator movement

• Unexpected drops in hydraulic pressure

• Fluid contamination or foaming in the reservoir

• Visible fluid seepage around seals or fittings

Diagnostic Techniques

• Visual inspection of hoses, seals, and fittings for wet spots or drips

• Pressure testing to detect pressure drops indicating internal leakage

• Ultrasonic leak detectors can identify leaks inside valves or cylinders

• Fluid analysis to check for contamination that may cause seal wear

Potential Causes

• Worn or damaged seals and O-rings inside valves or cylinders

• Loose or damaged fittings and connections

• Contaminated hydraulic fluid causing seal degradation

• Excessive system pressure stressing components

Prevention and Maintenance Tips

• Regularly inspect and replace seals and O-rings before failure

• Use clean, filtered hydraulic fluid to avoid contamination

• Tighten fittings to manufacturer specifications without over-tightening

• Monitor system pressure and avoid exceeding recommended limits

• Schedule routine maintenance checks focusing on leak-prone areas

  
  

Overheating in Hydraulic Systems

Symptoms to Look For

• Elevated fluid temperature beyond normal operating range (typically above 80°C or 176°F)

• Reduced system performance or sluggish response

• Fluid discoloration or burnt smell

• Damage to seals and hoses due to heat exposure

Diagnostic Techniques

• Use temperature sensors or infrared thermometers to monitor fluid temperature

• Inspect cooling system components such as heat exchangers and fans for blockages or failure

• Check fluid condition for signs of thermal breakdown

• Review system load and duty cycle for excessive heat generation

Potential Causes

• Insufficient cooling or blocked heat exchangers

• Excessive system load or continuous operation without rest

• Low fluid levels reducing heat dissipation

• High ambient temperatures affecting cooling efficiency

Prevention and Maintenance Tips

• Keep cooling systems clean and free of debris

• Maintain proper fluid levels and replace fluid according to schedule

• Avoid running the system at maximum load for extended periods

• Install temperature alarms to alert operators of overheating

• Use hydraulic fluids with appropriate viscosity and thermal stability

  
  

Cavitation in Hydraulic Systems

Symptoms to Look For

• Loud knocking or rattling noises from pumps or valves

• Erratic actuator movement or loss of power

• Visible damage or pitting on pump components

• Sudden drops in pressure or flow rate

Diagnostic Techniques

• Listen for unusual noises during operation, especially near pumps

• Inspect pump and valve surfaces for cavitation damage

• Check fluid levels and suction line for restrictions or leaks

• Use pressure gauges to monitor inlet and outlet pressures

Potential Causes

• Low fluid levels causing air to enter the pump

• Blocked or restricted suction lines

• Excessive pump speed or pressure settings

• Improper fluid viscosity or contamination

Prevention and Maintenance Tips

• Maintain correct fluid levels and avoid running dry

• Inspect and clean suction filters regularly

• Use proper hose sizes and avoid sharp bends in suction lines

• Adjust pump speed and pressure to manufacturer recommendations

• Use clean, correctly specified hydraulic fluid

  
  

Pressure Loss in Hydraulic Systems

Symptoms to Look For

• Slow or weak actuator movement

• Inconsistent or fluctuating system pressure readings

• Failure to reach required force or speed

• System alarms indicating low pressure

Diagnostic Techniques

• Use pressure gauges at various points to isolate pressure drops

• Inspect valves for internal leakage or malfunction

• Check for worn pump components reducing output pressure

• Examine hoses and fittings for leaks or damage

Potential Causes

• Internal leaks within valves or cylinders

• Worn or damaged pump components

• Blocked or partially closed valves

• Leaking hoses or fittings

Prevention and Maintenance Tips

• Perform regular pressure tests and monitor system performance

• Replace worn valves and pump parts promptly

• Keep hydraulic fluid clean to prevent valve sticking

• Inspect hoses and fittings regularly and replace damaged parts

• Train operators to avoid sudden pressure spikes or drops