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What must be done prior to starting up your piston pump for the first time?
  • Before starting the pump, FILL CASE WITH OIL – Failure to do so will damage the pump and void the warranty
  • Make sure that the direction of rotation and coupling alignment is correct
  • It is highly recommended that CLEAN petroleum oil, meeting or exceeding lubricating qualities of SAE 10W API service classification MS (Maximum Severity) is used. A system with contaminated oil will damage the pump and void the warranty.
  • When first starting the unit, it might be necessary to bleed the air from the pump outlet line to permit priming and reduce noise. Bleeding the air by loosening an outlet connection until a solid stream of fluid appears.
What are some of the common reasons my pump might be making excessive noise?
  • Worn pressure ring – replace immediately
  • Running in the wrong direction of the pump rotation – The direction of the rotation must correspond to the direction of the pump
  • Oil level is low – Make sure the reservoir is filled well above the end of the suction line
  • Incorrect Oil type – Make sure you are using a good, clean hydraulic oil with the necessary viscosity
  • Air leak(s) in the suction line, case drain line, or Shaft seal area – Identify if this is the case and tighten appropriately to avoid internal leakage
  • Pump running too fast – Reduce the speed as required – Any speed above the rating of the pump can be extremely dangerous and will lead to the premature pump failure
  • Coupling misalignment – Re-align the pump and motor
  • Reservoirs are not vented adequately – Vent the reservoir through the air filter
  • Flow restriction – Check the fittings and suction piping to make sure that full size is used throughout - Verify that the suction line is not plugged with any foreign material. It is suggested to avoid excessively long suction lines
  • Restricted filter or strainer – Clean filter and/or strainer
  • Worn or broken parts – Replace
  • Plugged reservoir air vent – Clean and/or replace
What are some of the reasons why my pump is running hot?
  • Pump drain line too close to the suction line – Locate the drain line in a location where it must travel the farthest distance possible before the oil re-enters the pump
  • The pump is being operated at higher pressures that are needed – Decrease the pump pressure
  • The pump is discharging through the relief valve – Adjust accordingly
  • Insufficient cooling – Increase reservoir capacity if applicable
  • Excessive friction – Some internal parts might be too tight – Remove the unit and evaluate
  • Low Oil in a reservoir – Increase the oil level to the recommended point
Why might my pump be leaking from the oil seal area?
  • Case pressure in pump case – Inspect the case drain line – Remove any restrictions
  • Contaminants on the shaft – Always protect the shaft from abrasive/foreign materials
  • Damaged shaft seal – Replace seal
  • Coupling misalignment – Re-align the pump and motor shafts
Why might my pump not be delivering the necessary pressure?
  • Pump running too slowly – Check the minimum speed recommendations
  • Oil is not being delivered by the pump – Suction line or suction filter clogged – Filters must be cleaned routinely, especially after the unit is first started – A thoroughly defined and exercised Preventive Maintenance program is critical to pump longevity
  • The pressure adjusting screw is not set high enough – set it accordingly
Why might the valve spool response be sluggish on my valve?
  • Solenoids are malfunctioning – Check for the proper source voltage and frequency – Remove the solenoid(s) and check fields
  • Contaminants in the system – Drain and flush the system – Disassemble and clean if necessary
  • Restricted drain – Small fittings or pipe
  • Distortion of the valve body – Align the body and piping to remove any possible strains
  • Pilot pressure is low – Check the pilot pressure system
Why might my pump not be delivering the necessary pressure?
  • Blocked drain – Inspect for any obstructions and foreign matter
  • Contaminants in the system – Disassemble, clean and flush
  • Pilot pressure not activated – Check the source of pilot pressure
  • Improper reassembly after a new installation – Use parts drawing to rule out incorrect assembly
  • Body distortion – Align the body to remove any straining
Why might my valve not be producing the necessary response?
  • Improper assembly of the valve(s) – Check parts and schematics
  • Spool installed backward – Reverse spool end
  • Improper installation of connections – Check installation schematics
Why might it be that my hydraulic motor is turning in the incorrect direction?
  • Incorrect piping between the control valve and motor – Check the circuit to determine the correct piping
Why might it be that my hydraulic motor is not turning over or not achieving desired speed/torque?
  • Relief valve sticking in the open position – Remove any debris that might be under the pressure adjustment ball or piston
  • System overload relief valve is not adjusted high enough – Check system pressure and reset the relief valve
  • Pump not delivering enough pressure or volume – Check the pressure and pump delivery
  • Free recirculation of oil to the reservoir being allowed through the system – The directional control valve may be in open center neutral or other return line open. Repair or replace the valve