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Top Tips for Hydraulic Power Pack Maintenance

Hydraulic Power Pack maintenance is key to maximising hydraulic system uptime. By implementing a thorough hydraulic maintenance program, application downtime can be kept to a minimum.


The hydraulic power pack is at the heart of hydraulic systems providing pressure and flow to operate hydraulic cylinders (linear motion) and hydraulic motors (rotary motion) which in turn produces power to drove complex heavy machinery.


With all the work they do, proper hydraulic power pack maintenance care is critical. Without it, you risk damaging the components, losing efficiency, and causing safety hazards.



Number 1 Top Tip: Oil Cleanliness!




50-70% of all hydraulic system failures can be linked to contamination! Maintaining an appropriate level of oil cleanliness is critical to the success of the hydraulic systems in any heavy equipment operation.



Three types of Hydraulic Maintenance

 There are three main types of hydraulic maintenance: reactive maintenance (RM), preventive maintenance (PM) and predictive maintenance (PdM).

Reactive maintenance stands for breakdown maintenance and involves the repairs that are done to fix the equipment that is already broken.

Preventive maintenance is regular maintenance that is performed on the equipment to prevent it from breaking down. Preventive Maintenance is implemented through a Preventive Maintenance Program.

Predictive Maintenance or condition-based maintenance uses sensor devices to collect information about the system and components and prompts the personnel to perform maintenance at the exact moment when it’s needed. Due to high costs and technical requirements, it is still new to the market and not used very often.


10 Top Tips for Hydraulic Preventative Maintenance

(Ensure you carry out the appropriate risk assessment before undertaking any HPP maintenance procedures.)

  1. Listen to the pump for making any unusual noise. The noise may be a sign of cavitation. Cavitation is the formation of bubbles or so-called cavities in the hydraulic fluid and is caused by the air that gathers in the areas of relatively low pressure around an impeller. It damages the pump, decreases the flow, and causes vibration if not treated. 
  2. Check system temperature using a built-in or spot infrared thermometer. If the temperature is higher than recommended by the manufacturer, check the condition of the cooler and relief valve settings.
  3. Sample hydraulic fluid for colour, visible signs of contamination, and odour.
  4. Inspect hydraulic hoses, tubing, and fittings for leaks and frays. Remember that any leakage is an environmental and safety hazard since hydraulic fluid gets hot inside the system and is highly toxic. If the fluid level gets too low, the system will operate at reduced capacity and will get overheated.
  5. Check breather caps, filters, and fill screens.
  6. Inspect inside of the hydraulic reservoir for any signs of aeration. Use a flashlight and investigate the fill hose for any signs of foaming or small whirlpools. Aeration may be a sign of a leak in the suction line or faulty shaft seals, so it’s important to inspect the reservoir on a regular basis.
  7. Check hydraulic fluid levels. Add hydraulic fluid of the same brand and viscosity grade if needed using portable filters when applicable.
  8. Inspect proportional/servo valves for overheating. High temperature means that the valve is sticking.
  9. Scan the electric drive motor with a handheld infrared thermometer for hot spots.
  10. Check return/pressure/hydraulic filter indicators and pressure gauges for readings.


To help you with your hydraulic power pack maintenance, please contact our experienced technical team at Neilson Hydraulics on 01709 821002/ E: sales@neilson-hydraulics.co.uk or visit our website at: https://www.neilson-hydraulics.co.uk/hydraulic-power-packs.html