Hydraulic System Maintenance Checklist and Tips

Hydraulic System Maintenance Checklist

Before starting on this checklist, you may want to have your system's literature with you, to check manufacturer specifications for things like filter schedules, oil specs and average temperatures.

Here is our collection of hydraulic system maintenance tips:

1. Oil Maintenance

Check your hydraulic oil on a consistent schedule — it needs to remain clean and free of any contaminants. You should empty and replace the hydraulic oil after every 1,000 hours of work or per the manufacturer's instructions.

You can help minimize the risk of contamination by keeping the area around entry points, like dipsticks and fuel plugs, clear of dust and debris.

Read the manufacturer specifications to confirm how often you should change the fluid and other factors of hydraulic fluid care. It is essential to use the same type of hydraulic fluid every time you top off your levels. If possible, use the same brand each time as well.

2. Changing Filters Regularly

Filters take on the task of removing even the most minuscule particles that could clog your hydraulic system. However, the process of keeping particulates out of the system causes the filters themselves to become clogged over time. Your filters will lose efficacy as they accumulate pollutants, so replace them often. If applicable, make sure to clean the filter bowl as well.

3. Rod Conditions

Visually inspect the rod for wear, such as corrosion and pitting. These issues can lead to moisture within the fluid, which compounds and can cause many problems for your hydraulic system, like increased wear and inadequate lubrication.

4. Seal Replacement

If rod corrosion occurs, it can damage the seal from excess friction. Other dangers to seals include excess pressure and fluid contaminants. A worn seal may leak, causing equipment hazards and environmental health and safety concerns. If there are signs the seal is damaged, check with your equipment manufacturer about proper replacement.

5. Regular Hydraulic Lines Checkup

Fluctuations in pressure or line thickness can lead to equipment damage. For example, excessive pressure from the cylinder can cause ballooning, where the line dilates and allows too much high-pressure fluid to pass, thus wearing out the seals. Regularly inspect the condition of the lines and make sure they are not ballooning.

6. Inspect Fluid Levels

For optimal functioning, you must watch your fluid levels, adding to them as needed. Too little hydraulic fluid can damage your pumps. Just like when replacing contaminated oil, be sure to follow the specifications given by the manufacturer and take care to avoid mixing oils.

7. Check Breather Caps, Fill Screens and Breather Filters

Breathers must be kept clean or risk contaminating the hydraulic system. Clean the breather regularly and inspect it for holes or tears. Different types of breathers may have additional requirements, so check the manufacturer's instructions. Spring types, for instance, may need to be replaced annually to avoid tension loss that allows contaminants. Others can have indicators that tell you when to replace filters or caps. Be aware of any additional steps such as these.

8. Inspect Filter Indicators

Most filters have pop-out buttons that trigger when they become clogged. Check for any of these indications and replace the filters as needed.

9. Visually Check All Pipes, Pipe Connections and System Hoses

If hoses are pinched, kinked, frayed, bubbling, stretched or otherwise damaged, they can restrict the flow of fluid or lead to pressure leaks. Most of these problems are visible from the outside, but others occur internally, so inspect the inside for damage that could cause a clog.

Additionally, check pipes, fittings and couplers for any dents or corrosion. Fittings should be snug, but not overly tight. Couplers need to stay clean to prevent contamination or leaking.

Leaks cause excessive oil consumption, overheating and severe safety and environmental hazards. These can be difficult to clean up and dangerous for employees, so watch out for signs to prevent leaks in the first place.

10. Check the System Temperature

If your system temperature gets too hot, it could indicate an issue with your cooler or relief valve. Low fluid levels could also contribute to heat. Use built-in or infrared thermometers to check temperatures. Do not touch components that you suspect may be hot, as this can lead to severe burns.

11. Visually Inspect Inside the Reservoir

Aeration within the reservoir can cause overheating and wear on seals and system components. Aeration happens when air bubbles enter the oil stream due to low fluid levels, low fluid temperatures, air leaks and bad seals. Foaming, loud gurgling noises and whirlpools at the suction strainer indicate aeration.

12. Listen to the Pumps

Similar to aeration, cavitation is the result of gas bubbles experiencing rapid changes in pressure. The gas bubbles implode, causing miniature shock waves. The shock waves generate repeated stress on the metal surfaces, damaging the components.

If a pump is cavitating, it will release a high-pitched whining sound. Listening to the pumps gives you an idea of cavitation that may be present.

13. Inspect a Sample of Hydraulic Fluid

To check your fluid for quality, take a small sample and inspect it. Do a quick visual inspection for color abnormalities and visible contaminants. You may also want to inspect for any unusual odors. Performing a contamination test can offer a more accurate review of the fluid's qualities. It offers detailed findings for particle contamination, water contamination, viscosity, acidity and signs of overheating.

14. Perform Hydraulic Valve Maintenance

Scan electrically controlled Servo valves using an infrared thermometer and check the temperature of these valves. If it is higher than 150℉, you may have a problem with the valve. Slow or errant operation at the valve points can be a sign of contaminated fluid.

15. Check the Electric Drive Motor

Keep your infrared thermometer out and use it on the electric drive motor to detect any areas of high heat. These areas could be on the housing or rotor bearings and require servicing to avoid further damage to the equipment.