Hydraulic System Repairs and Maintenance
Comprehensive hydraulic service for wind turbines – from pitch and yaw system maintenance to brake repairs and cylinder replacements. All services performed by GWO-certified technicians according to OEM procedures and safety standards.
Keeping your turbines running through expert hydraulic service
Hydraulic systems are essential for wind turbine safety and control. The pitch system adjusts blade angles for power optimisation and emergency feathering, while the yaw and rotor brake systems ensure safe nacelle positioning and controlled stops.
Our hydraulic service team specialises in both preventive maintenance and corrective repairs. We perform comprehensive system diagnostics to identify developing problems before they cause failures, and execute targeted repairs that restore full system functionality. When component replacement is necessary, we ensure correct installation and thorough system testing according to OEM specifications.
Comprehensive hydraulic service capabilities
Pitch System Hydraulic Service
The pitch system controls blade angle for power regulation and emergency feathering. Reliable hydraulic operation is critical for turbine safety and performance.
Pitch cylinder service:
• Cylinder inspection and seal replacement
• Rod and barrel condition assessment
• Mounting and pivot point inspection
• Stroke testing and position verification
Accumulator service:
• Pre-charge pressure verification
• Bladder and membrane inspection
• Nitrogen recharging
• Replacement when required
System maintenance:
• Hydraulic oil analysis and replacement
• Filter changes and contamination control
• Pressure testing and adjustment
• Leak detection and repair
• Emergency feathering system verification
Yaw System Hydraulic Service
The yaw system positions the nacelle into the wind and applies braking force to maintain orientation. Hydraulic yaw brakes require regular maintenance for reliable operation.
Yaw brake service:
• Brake caliper inspection and overhaul
• Brake pad measurement and replacement
• Hydraulic line inspection
• Pressure adjustment and calibration
Yaw motor hydraulics (where applicable):
• Motor inspection and seal replacement
• Valve block maintenance
• System pressure testing
System maintenance:
• Hydraulic fluid condition monitoring
• Filter replacement and system flushing
• Leak detection and repair
• Accumulator pre-charge verification
• Functional testing and calibration
Rotor Brake Hydraulic Service
The rotor brake provides emergency stopping capability and holds the rotor stationary during maintenance. This safety-critical system requires careful inspection and testing.
Brake caliper service:
• Caliper inspection and overhaul
• Piston seal replacement
• Brake pad inspection and replacement
• Disc condition assessment
Hydraulic power unit:
• Pump inspection and service
• Accumulator pre-charge verification
• Valve function testing
• Pressure switch calibration
System verification:
• Emergency stop function testing
• Brake application time measurement
• Holding torque verification
• Rotor lock engagement testing
• Complete system documentation
All rotor brake work follows strict safety procedures with redundant isolation and verification.
Repairs and replacements across all hydraulic systems
• Pitch cylinders
• Yaw brake cylinders
• Rotor brake cylinders
• Rotor lock actuators
• Auxiliary cylinders
• Rod seals and wipers
• Piston seals and guides
• Cylinder mounts and pivots
• Hydraulic pumps
• Electric motor drives
• Hydraulic power units
• Reservoirs and tanks
• Oil coolers
• Filters and breathers
• Level and temperature sensors
• Pressure relief valves
• Directional control valves
• Proportional valves
• Pressure control valves
• Flow control valves
• Check valves
• Accumulators
• Manifold blocks
• Hoses and fittings
Advanced diagnostics for hydraulic system health
We use advanced diagnostic techniques to assess hydraulic system condition, identify developing problems and determine the most effective repair strategy. Early detection prevents unexpected failures and reduces repair costs.
Comprehensive oil analysis to assess system health and identify wear patterns or contamination.
Analysis includes:
• Particle counting (ISO cleanliness)
• Water content measurement
• Viscosity verification
• Wear metal analysis
• Additive depletion assessment
Results guide maintenance decisions:
• Oil change intervals
• Filter upgrades
• Component inspection priorities
• Contamination source identification
Systematic pressure testing and leak detection to verify system integrity and identify problem areas.
Diagnostic methods:
• System pressure profiling
• Accumulator pre-charge testing
• Valve response measurement
• Cylinder drift testing
• Ultrasonic leak detection
Problem identification:
• Internal valve leakage
• Cylinder seal bypass
• Fitting and connection leaks
• Accumulator bladder failures
• Pump efficiency degradation
Structured methodology for reliable results
Our hydraulic service follows a systematic approach ensuring quality and safety:
1. Assessment and planning
Review of maintenance history, SCADA alarm analysis, visual inspection, scope definition and parts procurement
2. Preparation and isolation
Safety briefing, system depressurisation, LOTO procedures, energy isolation verification
3. Diagnostics and inspection
Pressure testing, leak detection, oil sampling, component condition assessment, documentation of findings
4. Repair or replacement
Component repair where feasible, new part installation per OEM specification, correct torque application, seal and fitting replacement
5. Testing and documentation
System flushing and filling, pressure calibration, functional testing, leak checks, complete service documentation
Hydraulic service for turbines from leading OEMs
GWO-certified team for safe hydraulic work
All hydraulic service is performed by personnel holding:
• GWO Certifications
BST (Basic Safety Training), BTT (Basic Technical Training), ART (Advanced Rescue Training) – complete package for wind turbine work
• Hydraulic Qualifications
Specialist training in hydraulic system diagnostics, repair procedures and safety protocols
• OEM Training
Manufacturer-specific training for pitch, yaw and brake hydraulic systems
• Lifting and Rigging
Certified for nacelle crane operations and heavy component handling
• Safety Training
Trained in high-pressure system hazards, stored energy isolation and emergency procedures
Need hydraulic service for your turbines?
Contact us to discuss your hydraulic service requirements. We offer rapid response for urgent repairs and flexible scheduling for planned maintenance across Central and Western Europe.