Checklist for Hydraulic System Care and Maintenance

Hydraulic systems have a variety of applications ranging from small-scale industries to large-scale industries. Recently, hydraulics has applications in automobiles, agriculture, mining, marine, aerospace, etc. So, utmost care is required to maintain these hydraulic systems and to avoid accidents. Proper maintenance of the hydraulic system and hydraulic fuel is necessary to minimize the premature breakdown of the system and to maximize uptime. So, in this article, we are discussing the checklist for hydraulic system maintenance and care.

Hydraulic Fluid Care

Hydraulic fluids such as oils play a vital role in the working of the hydraulic system. They act as the lifeblood of hydraulics. These fluids not only transfer pressure and energy but also provide lubrication and cooling to the system. The following four points are necessary to control the efficiency of hydraulic fluids used.

1. Control the Temperature of Fluids:

Temperature increases as a result of the continuous flow of liquid through the system. In conventional hydraulic systems, due to excessive temperature, varnish and sludge deposits are formed as a result of oil oxidization. Similarly, pump cavitation occurs as a result of too low temperature. However, in modern hydraulic systems that use servo-hydraulic valves, nitrogen fixation occurs as a result of extreme temperature. Use a hydraulic oil cooler or a large size reservoir to solve the issue of over-temperature

2. Keep the Hydraulic System Clean:

Eliminate the presence of contaminants such as dirt, water, cutting fluids, and metal particles from the hydraulic fluids. These foreign particles enter into the system through the reservoir cover, leaks in the suction lines, breather fill openings, etc. To protect the system from contaminants, always clean the area around dipsticks, and fill plugs and hydraulic filters before removing them for maintenance or checking.

3. Keep the Hydraulic Fluid Clean:

Storing hydraulic fluids unused for a long time will create deposits in the tank. So, always use good storage and handling practices to prevent contamination of fluids.

4. Keep an Oil Analysis Program:

According to OEM’s specification, hydraulic fluids need to maintain the required oil cleanliness level through the proper filtration methods. But the oil filtration interval can be changed depending on the working environment.

Hydraulic System Maintenance

A basic hydraulic system includes components like pumps, fluids, valves, pressure regulators, actuators, etc. All the analysis work carried out on hydraulic fluids will become effortless when the system itself fails. So, the top 10 hydraulic system management checklist is included below.

1. Check Fluid Levels:

Fluid levels need to be monitored a regular intervals. Add filtered oil if required and use the same oil brand and viscosity grade as directed by the manufacturer.

2. Inspect breather caps, breather filters and fill screens:

Breather caps and filters are used to prevent contaminants from entering into the system. So, don’t punch holes on these screens.

3. Check filter indicators and/or pressure differential gauges:

Replace the components that show any negative indications.

4. Inspect all Pipes, Pipe joints, and hoses for leaks and frays:

Excessive leakage of hydraulic fluids will cause environmental and safety hazards, high oil consumption, and overheating. So, diagnose such leakages from the beginning itself.

5. Use built-in thermometers or hand-held infrared detectors to check system temperature:

If the temperature rises above 140ºF check the check fluid quantity, relief valve settings, reservoir, and cooler operations

6. Inspect the reservoir for signs of aeration:

Aeration occurs when the air trapped in the hydraulic fluid circulates through the system. This results in pump aeration, low fluid levels, air leaks in the suction line, low fluid temperature, etc.

7. Inspect the pump for signs of cavitation:

Cavitation is the process of forming bubbles in hydraulic fluids. This will damage the working of pumps.

8. Inspect the sample of hydraulic fluid:

Check the color and odor of fluids to verify the level of contamination. Better use a Patch test Kit or a Laser Particle Counter and maintain the periodic oil analysis report.

9. Use an infrared thermometer to scan electrically controlled servo valves:

The temperature above 150ºF indicates that the valve is sticking.

10. Scan the electric drive motor:

Use an infrared thermometer to measure housing hot spots and rotor-bearing temperatures.