EXAMPLES OF WATER PUMP FAILURE MODES David Lewis Jan 2014.
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Transcript of EXAMPLES OF WATER PUMP FAILURE MODES David Lewis Jan 2014.
Failure modes
• Corrosion• Cavitation and Erosion• Electrolysis• Body damage (Cracking)• Dirt or incrustations• Excessive use of gasket sealant• Impeller cracks• Overload (Tension)
Corrosion
CAUSE
Use of Non specified manufacturer coolant
Top up with Water only
RESULT
Rust contaminates the cooling system and results in leakage.
Cavitation and Erosion CAUSE• Incorrect bleeding
of cooling system• Temperature
exceeds boiling point
RESULT• Loss of flow, holes
in casting leading to leakage
Electrolysis
CAUSE• Low PH value causes acidic
action.
• Incorrect coolant
RESULT
• Reduced flow and over heating
Body Damage (Cracking)
CAUSE• Over tightening of bolts• Non sequential tightening of
bolts• Porosity (Unlikely)
RESULT• Unable to fit pump• Pump leaks in service
Dirt or Incrustations
CAUSE• Engine not flushed
out when changing cooling system components
RESULT• Damages the
surface of the mechanical seal.
Excessive use of gasket sealant
CAUSE • Over application
to ensure it fits first time and doesn’t leak
RESULT• Sealant strands
detach and force themselves between the unitised seal
Impeller Cracks
CAUSE• Poor handling of
pumps
RESULT• Loss of interference
between impeller and centre spigot
• Gradual erosion of the impeller