Pump troubleshooting

If the pump does not deliver enough water   Engine may not be running at the rated speed.   Strainer, inlet valve or suction line may be clogged.   Suction line or fittings may be leaking air.   Mechanical seal may be worn and leaking air or water. Check weep hole.   There may be too much clearance between the impeller and the volute due to wear. For best performance refer to manufacturer's recommendations for proper adjustment.   Lining in suction hose may be collapsing. This rubber lining inside the fabric layers may have pulled together under the vacuum created by the pump.   Suction lift may be too high. At a 25 foot lift the pump delivers only about 50% of the water it delivers at a 10 foot lift.   The suction hose may be too long, causing excessive friction loss and reducing pump capacity.   Discharge head may be too high. Check hose or pipe friction losses. A larger hose or pipe may correct this condition.     If the pump does not deliver enough pressure   Engine may not be running at its rated speed.   Mechanical seal may be leaking. Check weep hole.   There may be too much clearance between the impeller and pump body or volute due to wear. For good performance, refer to the manufacturer's instructions for proper adjustment.     If the pump does not prime properly   Make sure the pump casing is filled with water.   Look in the suction line or fittings. Check to see that all fittings are tight in the suction line and make sure there is no leak in the hose itself.   Mechanical seal may be worn and leaking air.   Inlet valve rubber may be frozen to the seat.   Pump may be running too slowly.   The clearance between the impeller and the pump body or volute may be greatly worn. Refer to manufacturer's instruction manual for proper adjustment.   Suction lift may be too high. At sea level the pump should not be used on lifts in excess of 25 feet from the level of the water to the center of the impeller. Keep the pump as close to the water source as is safely possible.   Suction line or suction strainer may be clogged.   Water may be too warm for the suction lift being used (as the temperature of the water increases above 60oF, the practical suction lift will decrease) making pump priming difficult. It may be necessary to replace the water in the pump case with fresh cold water.