null
Troubleshooting Guide for Engine Driven Water Pumps

Troubleshooting Guide for Engine Driven Water Pumps

1st Jun 2019

At some stage during your engine drive water pumps life, you might come across a time where your pump is not performing like it should. As there are many factors that could be the cause of this, we have put together a checklist of the most common problems that can be checked to help you get your pump pumping again.

Problem :-

  • Pump Wont Prime after three minutes

Possible Cause & Solutions :-

  • Pump housing not filled with water. Fill pump housing with water.
  • Static suction head too high. Lower the pump closer to the water.
  • Suction hose too long. Reduce suction hose length.
  • Leaking suction hose. Repair hose or repair coupler seal.
  • Strainer plugged. Clean strainer. To eliminate debris collecting around the strainer, set the strainer in a submerged bucket.
  • Internal pump wear or damage. Perform a vacuum test:
  • Fill the pump with water and attach a vacuum gauge to the suction port. Remove the discharge hose and start the pump. Move the throttle to fast. The gauge should read at least 20 inch Hg. If the vacuum is low and the engine speed is correct, there is an internal problem with the pump (worn components, etc.). If the engine speed is too low, there is a problem with the engine (engine worn out, governor problem, etc.).

Problem :-

  • Low Discharge capacity or pressure

Possible Cause & Solutions :-

Maximum engine speed correct:

  • Excessive head loss due to restricted discharge hose or very long discharge hose. Increase hose size and/or shorten hose.
  • Worn impeller and volute. Pumping water containing abrasives can quickly wear out a general-purpose pump. Pump only clean water or use a Trash pump.
  • Damage and poor performance caused by cavitation. See cavitation troubleshooting below.

Maximum engine speed too slow:

  • Engine throttle lever not in fast position.
  • Not producing maximum power due to worn engine or governor problem.

Problem :-

  • Pump Cavitates

Possible Cause & Solutions :-

  • The strainer also may be clogged. Keep the strainer clean. To eliminate debris collecting around the strainer, set the strainer in a submerged bucket.
  • Static suction head too great and/or suction hose too long or too small in diameter. Always use the shortest suction hose possible. Keep the hose diameter equal to or greater than the pump's suction port.

Problem :-

  • Pump Housing Cracked or Broken

Possible Cause & Solutions :-

  • Vehicle ran over discharge hose. Reposition and/or protect discharge hose.
  • Water left in pump housing and allowed to freeze. Always drain water from pump housing after using.
  • Water hammer damage caused by shutting water flow off very quickly (or driving over hose) with very long discharge hose length. Shut hose off more slowly or decrease discharge hose length.

Problem :-

  • Water leaking from in between pump casing and engine

Possible Cause & Solutions :-

  • Worn mechanical seal. Seal wear is usually caused by pumping water containing abrasives, running the pump dry, or shutting off water flow for a long period of time.

Problem :-

  • Engine does not turn over

Possible Cause & Solutions :-

  • Debris lodged in impeller/volute.