Replacing a Gear Pump
Pump displacement determins the flow rate a gear pump will produce. Generally when replacing a pump try to find one with similar displacement to that of the original. This will result in performance as it was originally designed.
Pump Displacements are in C.I.R. (cubic inches displacement per shaft revolution). Our website lists pumps in displacement order when performing searches.
To select a replacement for a broken or worn out hydraulic pump or motor that has no nameplate or has no rating marked on its case, make the internal physical measurements and then use our Gear Pump Sizing calculator below.

Make all measurements in inches, as accurately as possible. Convert fractional dimensions into decimal equivalents for use in the calculator.
  • 1. Measure gear width, W
  • 2. Measure bore diameter of one of the gear chambers: this is D
  • 3. Measure distance across both gear chambers; this is L
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      Gear Pump Sizing Calculator  
     
      Gear Width   W   inches  
      Bore Diameter    D   inches  
      Distance Across Gear Chanbers    L   inches  
         
      Displacement:    cu in