Agricultural Engineering Safety Lesson Plan: Hydraulic System Safety


To identify potential hazards associated with hydraulics and be aware of the recommendations for avoiding injury.


The use of hydraulics in agricultural and industrial applications has multiplied many times over the years because of its flexibility, simplicity, compactness, economy and safety. However, even with the best of care, hydraulic system component failure will occur and then the stage is set for accidents to happen unless care is taken during troubleshooting, repair and maintenance of the system.


  1. Always wear eye protection and appropriate clothing when working on hydraulic systems.
  2. Block up working units, such as a combine header, when you must work on the hydraulic system with the unit raised. Never rely on hydraulics to keep you safe in this kind of situation.
  3. Never service the hydraulic system while the machine's engine is running unless absolutely necessary, such as when bleeding the system.
  4. Do not remove cylinders until the working units are resting on the floor or ground, on safety stands or on blocks. Be sure the machine's engine is shut off during this procedure.
  5. Before disconnecting oil lines, relieve all hydraulic pressure and discharge the accumulator, If used.
  6. Be sure that all line connections are tight and the lines are not damaged. Escaping oil under pressure is a fire hazard and can penetrate the skin causing serious injury. Keep hands and body away from pinhole leaks and nozzles which eject fluids under pressure. Use a piece of cardboard or paper when searching for leaks. Do NOT use your hand. If ANY fluid is injected into the skin, it must be surgically removed within a few hours by a doctor familiar with this type of injury or gangrene may result.
  7. Always lower hydraulic working units to the ground before leaving the machine.
  8. When transporting the machine, lock the cylinder stops to hold working units solidly in place.
  9. Some hydraulic pumps, motors and valves are heavy. Before removing them, provide a means of support such as a chain hoist, floor jack or blocks.
  10. To insure adequate control of the unit, keep the hydraulics in proper adjustment.
  11. Be sure to couple hoses correctly. If the hoses are interchanged, equipment may operate in reverse and this could result in serious injury.
  12. Always repair components with external leaks and clean up any spilled oil as this may cause a bad fall.
  13. Use care in storing and handling fluids to keep out dirt and moisture. Store inside when possible. If stored outside, lay oil barrels on their sides. If not possible, tilt slightly so bung is at the high side. Keep oil bungs drawn tight. Revise oil containers and funnels in fuel after use. Store in clean area or cover to keep out dirt. When adding oil, clean all dirt from around the filler cap before removing it.
  14. Always be sure that all belts, pulling and rotating shafts are covered with appropriate guards.

Kansas State University Cooperative Extension Service, Manhattan, Kansas.

The KSU Cooperative Extension Service provides practical, research-based information and educational programs to address critical issues facing individuals, families, farms, businesses and communities.

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