Hydraulic System Care - 2012-11

Hydraulic System Checklist    

Hydraulic Reservoir


  • Visually inspect the oil level. The level should be between 1/4 and 3/4 of the sight glass. 
    • With the shelf package fully lowered the oil level will be at about 1/4 height on the sight glass.
    • With the shelf package fully raised the oil level will be at about 3/4 height on the sight glass.
  • Inspect for any visible oil around the hydraulic system.
  • With the shelf package down test for the proper stoppering pressure.

The proper stoppering pressure can be found in the owner's manual or your company's SOP.


Every 5 - 7 Years: 

Disassemble the hydraulic power pack

  • Inspect the high pressure hose for possible damage.
  • Thoroughly clean the reservoir interior.
  • Clean the metal suction screen.
  • Refill with new hydraulic oil.

Hydraulic Ram

The vacuum sealing o-rings for the hydraulic ram need to be serviced every 3 to 5 years. This is both the ram o-rings and the vacuum flange o-rings if an external vacuum sealing gland is used.


System Pressure

The system pressure should be checked annually. The proper pressure setting is in the documentation received with the machine.


Shelf Operation

The downward shelf operation should be smooth and not chattering. If there is chattering the flow control valve located near the hydraulic power pack reservoir should be adjusted. This adjustment and location is explained in the owner’s manual.



Also see our Tech Tip on Shelf Hydraulics Problems

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Tech Tips Home

These technical tips are for use by qualified maintenance personnel who are familiar with their specific freeze drying equipment. These tips are intended only as general guidelines. Lyophilization equipment is frequently custom configured and some tips may not be appropriate for all freeze dryers. Always read and follow the directions of your equipment's maintenance manual. If you would like to discuss one of our tech tips, please contact Dave Clayton at 215-672-7800 ext-1376.


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For SP Service & Support Enquiries - Including Spare Parts

Email: service@spscientific.com

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