Here are some basic steps when troubleshooting hydraulic problems:
- Obtain class room and hands-on training.
- Review the operating manuals.
- Review the schematics and bills of materials.
- Obtain and read the past field reports to learn and understand past repairs and maintenance that have been done on the system prior to problems.
- Look up the components on the internet to obtain specification sheets.
- Prepare to safely perform the work. Follow all mill procedures regarding working with hydraulic systems.
- Obtain and setup adequate lighting.
- Look over the hydraulic unit, mark up the direction of flow, if the valves are to be normally open or closed.
- Clean the hydraulic unit and surrounding area.
- Mark the various devices with "normal" operating parameters by tagging with the value or range, such as pressure, temperatures, flow rates, etc.
- Investigate the symptoms of the issues and what events occurred prior to failure.
- Investigate what the hydraulic unit is providing pressure for, such as a roll, hydraulic cylinder, or other component. Has the component failed? If a new component, are there any possible issues such as hoses that have been connected incorrectly, an incorrect device installed, other faults?
- Use hydraulics system operations and troubleshooting knowledge to understand what might have happened.
- Proceed systematically, using Occam's Razor philosophy – the simpler answer is usually the correct one.
- operating parameters
- pump direction
- oil temperature
- line temperatures
- filter condition
- oil quality
- air entrainment in the oil
- air bleed vents
- relief valves.
Finally, contact other resources for input/clarity on other questions you may have.
For more help with your hydraulic issues, contact your Valmet representative. The PM Maintenance School covers many topics.