Thank you fro watching! A vane pump is a fixed displacement pump, which means the only way to vary the flow is by changing the speed of the electric or Diesel engine. They also can not vary the pressure output. A Servo pump is in almost all cases a piston pump. They can vary the flow and pressure with an electrical signal that controls the compensator on the pump to make that variation.
wow!!! not replacing the shaft seal is a big NO!!!! NO!!! If the seal sucks air in your new cartridge will be toast. A 8 Doller new seal is well worth it.
