A Plastic Molding Plant
in the Upper Mid-West

The plastic molder had 10 new machines that were less than six months old. All of the machines were experiencing more than 10 percent down time due to hydraulic problems.

The problems were identified as:

  • Servo valve malfunction and failure
  • Over heating causing machine shut down
  • Pump failures

Application specific analysis was performed and the following was determined:

  • The hourly production value was greater than $200.00
  • Operating temperatures exceeded 190 degrees F
  • Servo valve circuit contamination level exceeded 20/18/16
  • Reservoir tops were removed and fans placed to blow on the oil for cooling
  • Oil reservoir capacity was only 20% used

Application specific solutions were implemented:

  • Kidney loop circuits with proper filter and water-oil heat exchanger were installed
  • Additional oil was added to the reservoir
  • Setting on Hot oil shutoff was lowered and changed to a warning before shutoff


  • Operating temperatures ran at or below 140 degrees F
  • Operating cleanliness ran at 15/13/10 or better
  • Machines experienced less than one half of one percent downtime for the first year after installation